Math · Algebra 2 ★★★ Hard UNIT 6 OF 0

Radical Functions — Free Algebra 2 Review Games.

This unit covers nth roots, rational exponents and solving radical equations — essential concepts for Algebra 2. Use our interactive study games to test your understanding, or review questions in traditional format below.

📋 115 questions ⏱ ~25 min
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All 115 questions below, each with the worked answer and a written explanation. Click any question to expand it.

Q1. Simplify: \(\sqrt{81}\)
A \(9\)
B \(27\)
C \(18\)
D \(81\)

\(9^2 = 81\), so \(\sqrt{81} = 9\).

Q2. What is the cube root of 27?
A 3
B 9
C 27
D 6

3^3 = 27, so the cube root of 27 is 3.

Q3. Rewrite \(x^{1/2}\) as a radical.
A \(\sqrt{x}\)
B \(\frac{x}{2}\)
C \(2\sqrt{x}\)
D \(x^2\)

\(x^{1/2} = \sqrt{x}\) by definition of rational exponents.

Q4. Simplify: \(x^{2/3}\) means:
A Cube root of \(x^2\)
B Square root of \(x^3\)
C \(\frac{x^2}{3}\)
D \(\frac{2x}{3}\)

\(x^{a/b}\) means the \(b\)-th root of \(x^a\).

Q5. What is the domain of \(f(x) = \sqrt{x}\)?
A \(x \geq 0\)
B All real numbers
C \(x > 0\)
D \(x \neq 0\)

Square root requires non-negative input: \(x \geq 0\).

Q6. Simplify: (8)^(2/3)
A 4
B 2
C 16
D 6

Cube root of 8 = 2, then 2^2 = 4.

Q7. Simplify: \(\sqrt{x^6}\)
A \(x^3\)
B \(|x^3|\)
C \(x^6\)
D \(x^2\)

\(\sqrt{x^6} = x^3\) (assuming \(x \geq 0\)).

Q8. Solve: \(\sqrt{x + 5} = 3\)
A \(4\)
B \(14\)
C \(-2\)
D \(8\)

Square both sides: \(x + 5 = 9\), \(x = 4\).

Q9. Simplify: (27)^(1/3)
A 3
B 9
C 27
D 1/3

The cube root of 27 is 3.

Q10. What is the domain of \(f(x) = \sqrt{x - 4}\)?
A \(x \geq 4\)
B \(x > 4\)
C \(x \geq 0\)
D All reals

\(x - 4 \geq 0\), so \(x \geq 4\).

Q11. Solve: \(\sqrt{2x + 1} = x - 1\)
A \(x = 4\)
B \(x = 0\)
C \(x = 4\) or \(x = 0\)
D \(x = 1\)

Square: \(2x+1=x^2-2x+1\), \(x^2-4x=0\), \(x(x-4)=0\). Check \(x=4\): \(\sqrt{9}=3=4-1\). Check \(x=0\): \(\sqrt{1}=1\) but \(0-1=-1\). Only \(x=4\) works.

Q12. Simplify: \((x^{3/4})^{4/3}\)
A \(x\)
B \(x^{1/4}\)
C \(x^{7/12}\)
D \(x^4\)

Multiply exponents: \((3/4)\cdot(4/3) = 1\), so \(x^1 = x\).

Q13. Solve: cube_root(x - 1) = -2
A -7
B 9
C -9
D 7

Cube both sides: x - 1 = -8, x = -7.

Q14. Simplify: \(\sqrt{12x^3}\)
A \(2x\sqrt{3x}\)
B \(4x\sqrt{3}\)
C \(6x\sqrt{x}\)
D \(2x^2\sqrt{3}\)

\(\sqrt{4 \cdot 3 \cdot x^2 \cdot x} = 2x\sqrt{3x}\).

Q15. Solve: \(\sqrt{x} + \sqrt{x-5} = 5\)
A \(9\)
B \(25\)
C \(4\)
D \(16\)

Isolate one radical: \(\sqrt{x} = 5-\sqrt{x-5}\). Square: \(x = 25-10\sqrt{x-5}+x-5\). \(10\sqrt{x-5} = 20\), \(\sqrt{x-5}=2\), \(x-5=4\), \(x=9\). Check: \(3+2=5\). Correct.

Q16. What is the value of 4^(1/2)?
A 2
B 1
C 8
D 16

4^(1/2) means the square root of 4. Since 2^2 = 4, the answer is 2. Choice D (16) is a common error from multiplying 4 by 4 instead of taking the square root.

Q17. What is the 4th root of 81?
A 3
B 9
C 27
D 20.25

The 4th root of 81 is the number that when raised to the 4th power equals 81. Since 3^4 = 81, the answer is 3. Choice B (9) is the square root of 81, not the 4th root.

Q18. Which value equals 25^(1/2)?
A 5
B 12.5
C 625
D 50

25^(1/2) means the square root of 25. Since 5^2 = 25, the answer is 5. Choice B (12.5) comes from treating the exponent as division (25 divided by 2), which is an incorrect interpretation of rational exponents.

Q19. Simplify: 5th root of (-32)
A -2
B 2
C -4
D Not a real number

Odd-indexed roots of negative numbers are real. Since (-2)^5 = -32, the 5th root of -32 is -2. Choice D is incorrect because only even-indexed roots of negative numbers are undefined in the real numbers; odd-indexed roots are always defined for all real inputs.

Q20. Which expression is equivalent to the 6th root of \(x\)?
A \(x^{1/6}\)
B \(x^6\)
C \(6x\)
D 6 times the square root of \(x\)

The \(n\)th root of \(x\) is written as \(x^{1/n}\). So the 6th root of \(x\) equals \(x^{1/6}\). Choice B, \(x^6\), is \(x\) raised to the 6th power, which is the opposite operation of taking a root.

Q21. Simplify: \(\sqrt{144}\)
A \(12\)
B \(72\)
C \(24\)
D \(14.4\)

\(\sqrt{144} = 12\) because \(12 \times 12 = 144\). Choice B (\(72\)) is simply \(144\) divided by \(2\), which is not the same as taking the square root.

Q22. What is the domain of $f(x) = $ cube root of \(x\)?
A All real numbers
B \(x \geq 0\)
C \(x > 0\)
D \(x \geq -1\)

The cube root is an odd-indexed radical and is defined for all real numbers, including negative inputs. Unlike square roots, cube roots do not require non-negative inputs. Choice B describes the domain of \(f(x) = \sqrt{x}\), not the cube root function.

Q23. Simplify: 16^(3/4)
A 8
B 4
C 12
D 64

16^(3/4) = (16^(1/4))^3. The 4th root of 16 is 2 since 2^4 = 16, and then 2^3 = 8. Choice D (64) comes from computing 16^3 first and then dividing by 4, which is not how rational exponents are evaluated.

Q24. Simplify: \(\sqrt{50x^4}\)
A \(5x^2\sqrt{2}\)
B \(5x\sqrt{2}\)
C \(25x^2\sqrt{2}\)
D \(10x^2\)

Factor the radicand: \(\sqrt{50x^4} = \sqrt{25 \cdot 2 \cdot x^4} = \sqrt{25} \cdot \sqrt{x^4} \cdot \sqrt{2} = 5 \cdot x^2 \cdot \sqrt{2}\). Choice B, \(5x\sqrt{2}\), incorrectly extracts only \(x\) instead of \(x^2\), since \(\sqrt{x^4} = x^2\), not \(x\).

Q25. Solve: \(\sqrt{3x - 2} = 4\)
A \(x = 6\)
B \(x = 2\)
C \(x = 7\)
D \(x = 18\)

Square both sides to get \(3x - 2 = 16\). Then \(3x = 18\) and \(x = 6\). Check: \(\sqrt{3(6) - 2} = \sqrt{16} = 4\), which is confirmed. Choice C (\(x = 7\)) comes from forgetting to subtract \(2\) from \(16\) before dividing by \(3\).

Q26. Simplify: x^(1/2) * x^(1/3)
A x^(5/6)
B x^(1/6)
C x^(2/3)
D x^(1/5)

When multiplying powers with the same base, add the exponents: 1/2 + 1/3 = 3/6 + 2/6 = 5/6. So x^(1/2) * x^(1/3) = x^(5/6). Choice B (x^(1/6)) comes from subtracting 1/3 from 1/2 instead of adding.

Q27. Simplify: \((x^3 y^6)^{1/3}\)
A \(x y^2\)
B \(x^3 y^2\)
C \(x^{1/3} y^2\)
D \(x y^{1/3}\)

Apply the exponent \(1/3\) to each factor inside: \((x^3)^{1/3} = x^{3/3} = x\), and \((y^6)^{1/3} = y^{6/3} = y^2\). Choice C makes the error of applying the \(1/3\) exponent to \(x\) itself rather than to \(x^3\), producing \(x^{1/3}\) instead of \(x\).

Q28. What is the domain of \(f(x) = \sqrt{3 - 2x}\)?
A \(x \leq 3/2\)
B \(x \geq 3/2\)
C \(x \geq -3/2\)
D All real numbers

The radicand must be non-negative: \(3 - 2x \geq 0\). Solving gives \(-2x \geq -3\). Dividing by \(-2\) and flipping the inequality yields \(x \leq 3/2\). Choice B reverses the inequality direction, which is the most common error when dividing by a negative coefficient.

Q29. Solve: \(\sqrt{x + 3} = x - 3\)
A \(x = 6\) only
B \(x = 1\) only
C \(x = 1\) and \(x = 6\)
D No solution

Square both sides: \(x + 3 = (x - 3)^2 = x^2 - 6x + 9\). Rearranging: \(x^2 - 7x + 6 = 0\), which factors as \((x - 6)(x - 1) = 0\). Checking \(x = 1\): \(\sqrt{4} = 2\), but \(1 - 3 = -2\), so \(x = 1\) is extraneous. Checking \(x = 6\): \(\sqrt{9} = 3 = 6 - 3\), which is confirmed. Choice C is a common error that skips checking for extraneous solutions.

Q30. Simplify: 32^(2/5)
A 4
B 8
C 2
D 16

32^(2/5) = (32^(1/5))^2. The 5th root of 32 is 2 since 2^5 = 32, and then 2^2 = 4. Choice B (8) results from mistakenly cubing instead of squaring: 2^3 = 8, which would correspond to an exponent of 3/5, not 2/5.

Q31. Simplify: cube root of \((54x^3)\)
A \(3x\) times the cube root of \(2\)
B \(3x\) times the cube root of \(6\)
C \(6x\) times the cube root of \(3\)
D \(x\) times the cube root of \(54\)

Factor \(54\) as \(27 \cdot 2\): cube root of \((27 \cdot 2 \cdot x^3)\) = cube root of \(27\) times cube root of \(x^3\) times cube root of \(2\) = \(3 \cdot x \cdot\) cube root of \(2\). Choice B uses cube root of \(6\) because \(54 = 9 \cdot 6\), but \(9\) is not a perfect cube, so that factoring does not extract any whole number from under the radical.

Q32. If f(x) = x^(3/2), what is f(4)?
A 8
B 6
C 4
D 12

f(4) = 4^(3/2) = (4^(1/2))^3 = 2^3 = 8. Choice B (6) comes from treating the exponent as multiplication: 4 times 3/2 = 6. This is incorrect because the base is raised to the exponent, not multiplied by it.

Q33. Which expression is equivalent to \(x^{-1/3}\)?
A \(1\) divided by the cube root of \(x\)
B Negative cube root of \(x\)
C Cube root of negative \(x\)
D \(x^3\)

A negative exponent indicates a reciprocal: \(x^{-1/3} = 1 / x^{1/3} = 1\) divided by the cube root of \(x\). Choice B is a common misconception. The negative sign in the exponent does NOT make the expression negative; it places the expression in the denominator as a reciprocal.

Q34. Solve: \(\sqrt{x + 6} = \sqrt{x} + 1\)
A \(x = 25/4\)
B \(x = 7\)
C \(x = 5\)
D \(x = 3/2\)

Square both sides: \(x + 6 = (\sqrt{x} + 1)^2 = x + 2\sqrt{x} + 1\). Simplifying gives \(5 = 2\sqrt{x}\), so \(\sqrt{x} = 5/2\) and \(x = 25/4\). Check: \(\sqrt{25/4 + 6} = \sqrt{49/4} = 7/2\), and \(\sqrt{25/4} + 1 = 5/2 + 1 = 7/2\), which is confirmed. Choice B (\(x = 7\)) results from incorrectly squaring the right side as if \((\sqrt{x} + 1)^2 = x + 1\), omitting the cross term.

Q35. Simplify: (x^(2/3) * y^(1/2)) / (x^(1/3) * y^(3/2))
A x^(1/3) / y
B x^(1/3) * y
C x / y^2
D x^(1/3) / y^2

Subtract exponents when dividing like bases: x^(2/3 - 1/3) = x^(1/3), and y^(1/2 - 3/2) = y^(-1) = 1/y. The result is x^(1/3) / y. Choice B ignores the negative exponent on y, incorrectly keeping y in the numerator instead of moving it to the denominator.

Q36. Solve: \(\sqrt{x - 3} + \sqrt{x + 5} = 4\)
A \(x = 4\)
B \(x = 7\)
C \(x = 3\)
D \(x = 11\)

Isolate one radical: \(\sqrt{x - 3} = 4 - \sqrt{x + 5}\). Square both sides: \(x - 3 = 16 - 8\sqrt{x + 5} + (x + 5)\). Simplify to get \(8\sqrt{x + 5} = 24\), so \(\sqrt{x + 5} = 3\) and \(x = 4\). Check: \(\sqrt{1} + \sqrt{9} = 1 + 3 = 4\), confirmed. Choice B fails because \(\sqrt{4} + \sqrt{12}\) equals \(2 + 2\sqrt{3}\), which is not equal to \(4\).

Q37. If f(x) = x^(2/3), what is f(-27)?
A 9
B -9
C -3
D Not a real number

f(-27) = (-27)^(2/3) = ((-27)^(1/3))^2 = (-3)^2 = 9. The cube root of -27 is -3, which is real, and squaring -3 yields a positive result of 9. Choice B is wrong because (-3)^2 = 9, not -9. Choice D is incorrect because the index 3 is odd, so cube roots of negative numbers are always real.

Q38. Solve: \(2\sqrt{x - 1} - \sqrt{2x - 1} = 1\)
A \(x = 5\)
B \(x = 1\)
C \(x = 5\) and \(x = 1\)
D \(x = 2\)

Isolate the radical: \(\sqrt{2x - 1} = 2\sqrt{x - 1} - 1\). Let \(u = \sqrt{x - 1}\); then \(2x - 1 = 2u^2 + 1\), so \(\sqrt{2u^2 + 1} = 2u - 1\). Squaring both sides: \(2u^2 + 1 = 4u^2 - 4u + 1\), giving \(2u^2 - 4u = 0\), so \(u = 0\) or \(u = 2\). When \(u = 0\), \(x = 1\): checking gives \(2(0) - \sqrt{1} = -1\), which is not \(1\), so \(x = 1\) is extraneous. When \(u = 2\), \(x = 5\): checking gives \(2(2) - \sqrt{9} = 4 - 3 = 1\), confirmed. Choice C ignores the extraneous solution.

Q39. Expand and simplify: \((\sqrt{x} + \sqrt{y})^2\)
A \(x + 2\sqrt{xy} + y\)
B \(x + y\)
C \(\sqrt{x^2 + y^2}\)
D \(x + y + \sqrt{xy}\)

Apply the square of a binomial pattern \((a + b)^2 = a^2 + 2ab + b^2\) with \(a = \sqrt{x}\) and \(b = \sqrt{y}\): \((\sqrt{x})^2 + 2\sqrt{x}\sqrt{y} + (\sqrt{y})^2 = x + 2\sqrt{xy} + y\). Choice B is the most common error, omitting the cross term \(2\sqrt{xy}\) entirely. Choice D has the correct structure but divides the cross term by \(2\) instead of multiplying.

Q40. For what values of x does \(\sqrt[3]{x^2 - 4}\) equal \(\sqrt[3]{3x}\)?
A \(x = 4\) and \(x = -1\)
B \(x = 4\) only
C \(x = -1\) only
D \(x = 4\) and \(x = 1\)

Because the cube root function is one-to-one, \(\sqrt[3]{a}\) equals \(\sqrt[3]{b}\) implies \(a = b\). Setting \(x^2 - 4 = 3x\) gives \(x^2 - 3x - 4 = 0\), which factors as \((x - 4)(x + 1) = 0\). Both \(x = 4\) and \(x = -1\) are valid because cube roots accept all real inputs, so no extraneous solutions arise. Choice D replaces \(-1\) with \(1\), but checking \(x = 1\) gives \(\sqrt[3]{-3}\) on the left and \(\sqrt[3]{3}\) on the right, which are not equal.

Q41. What is the value of the cube root of -125?
A -5
B 5
C -25
D 25

The cube root of -125 is -5 because (-5)^3 = -125. Odd-index roots of negative numbers are real and negative. Choice B ignores the negative sign. Unlike square roots, cube roots of negative numbers are defined in the real number system.

Q42. Simplify: \(\sqrt{100x^2}\) for \(x \geq 0\)
A \(10x\)
B \(50x\)
C \(10x^2\)
D \(100x\)

\(\sqrt{100x^2} = \sqrt{100} \cdot \sqrt{x^2} = 10 \cdot x = 10x\) for \(x \geq 0\). Choice B is wrong because \(\sqrt{100} = 10\), not \(50\). Choice C is wrong because \(\sqrt{x^2} = x\) (not \(x^2\)) when \(x \geq 0\). Choice D mistakenly keeps \(100\) inside instead of taking its square root.

Q43. What is the value of 16^(3/4)?
A 8
B 4
C 12
D 64

Rewrite as (16^(1/4))^3. Since 2^4 = 16, the fourth root of 16 is 2. Then 2^3 = 8. Choice B = 4 results from computing 16^(1/2) instead of 16^(3/4). Choice D = 64 would equal 16^(3/2), which uses the wrong denominator in the exponent.

Q44. What is the domain of \(f(x) = \sqrt{x + 9}\)?
A \(x \geq -9\)
B \(x \geq 9\)
C \(x \geq 0\)
D all real numbers

For a square root to be defined, the radicand must be non-negative: \(x + 9 \geq 0\), which gives \(x \geq -9\). Choice B incorrectly makes the bound positive. Choice C would only be correct if the function were \(\sqrt{x}\). Choice D applies to cube root (odd-index) functions, not square roots.

Q45. Which expression is equivalent to \(\sqrt[3]{x^2}\)?
A \(x^{2/3}\)
B \(x^{3/2}\)
C \(x^{1/3}\)
D \(2x^{1/3}\)

The nth root of \(x^m\) equals \(x^{m/n}\). Here \(n = 3\) and \(m = 2\), so the result is \(x^{2/3}\). Choice B = \(x^{3/2}\) swaps numerator and denominator, which is the square root of \(x^3\), not the cube root of \(x^2\). Choice C = \(x^{1/3}\) is the cube root of \(x\), missing the exponent on \(x\).

Q46. Simplify: the fourth root of 81
A 3
B 9
C 27
D 4

The fourth root of 81 equals 81^(1/4). Since 3^4 = 81, the answer is 3. Choice B = 9 is the square root of 81, not the fourth root. Choice C = 27 is 3^3, not 3^4. Choice D = 4 confuses the index of the radical with its value.

Q47. Which of the following equals \(\sqrt{x} \cdot \sqrt{x}\) for \(x \geq 0\)?
A \(x\)
B \(x^2\)
C \(2x\)
D \(2\sqrt{x}\)

\(\sqrt{x} \cdot \sqrt{x} = (x^{1/2})^2 = x^1 = x\). Alternatively, \(\sqrt{x \cdot x} = \sqrt{x^2} = x\) for \(x \geq 0\). Choice B = \(x^2\) would require \((\sqrt{x})^4\). Choice C = \(2x\) incorrectly treats multiplication of two radicals as adding coefficients. Choice D = \(2\sqrt{x}\) confuses multiplication with doubling.

Q48. Simplify: \((x^4)^{1/2}\) for \(x \geq 0\)
A \(x^2\)
B \(x^{1/2}\)
C \(x^4\)
D \(x^8\)

By the power of a power rule, multiply the exponents: \((x^4)^{1/2} = x^{4 \cdot 1/2} = x^2\). Choice B = \(x^{1/2}\) results from dividing exponents (\(4 / (1/2)\)) is not what the rule says — the rule is multiply, not divide. Choice C removes the outer exponent entirely. Choice D = \(x^8\) results from multiplying \(4\) by the denominator alone (\(4 \cdot 2 = 8\)) instead of by the fraction \(1/2\).

Q49. Simplify: \(\sqrt{72}\)
A \(6\sqrt{2}\)
B \(8\sqrt{2}\)
C \(4\sqrt{18}\)
D \(36\sqrt{2}\)

Factor out the largest perfect square: \(72 = 36 \cdot 2\), so \(\sqrt{72} = \sqrt{36} \cdot \sqrt{2} = 6\sqrt{2}\). Choice D = \(36\sqrt{2}\) results from pulling out the factor \(36\) without taking its square root. Choice C = \(4\sqrt{18}\) simplifies further to \(4 \cdot 3\sqrt{2} = 12\sqrt{2}\), which is not fully simplified and is not equal to \(6\sqrt{2}\).

Q50. Solve for x: \(\sqrt{3x + 4} = 7\)
A \(15\)
B \(1\)
C \(5\)
D \(45\)

Square both sides: \(3x + 4 = 49\). Subtract 4: \(3x = 45\). Divide by 3: \(x = 15\). Verify: \(\sqrt{3(15) + 4} = \sqrt{49} = 7\). Choice B = \(1\) results from not squaring the right side and solving \(3x + 4 = 7\) directly. Choice D = \(45\) is the intermediate value \(3x = 45\) before the final division by 3.

Q51. Simplify: \((27x^6)^{2/3}\)
A \(9x^4\)
B \(3x^4\)
C \(9x^9\)
D \(18x^4\)

Apply the rational exponent to each factor. For 27: \(27^{2/3} = (27^{1/3})^2 = 3^2 = 9\). For \(x^6\): \((x^6)^{2/3} = x^{6 \cdot 2/3} = x^4\). Result: \(9x^4\). Choice B = \(3x^4\) stops after the cube root step without squaring (\(27^{1/3} = 3\) only). Choice C = \(9x^9\) uses the reciprocal exponent on x: \(x^{6 \cdot 3/2} = x^9\).

Q52. What is the range of \(f(x) = \sqrt{x - 2}\)?
A \(y \geq 0\)
B \(y \geq 2\)
C \(y \geq -2\)
D all real numbers

The domain is \(x \geq 2\), but the range describes the output values. A square root always produces non-negative outputs, so \(f(x) \geq 0\) for all valid x, giving range \(y \geq 0\). Choice B confuses the domain restriction \(x \geq 2\) with the range. Choice D applies to cube root functions, which can output all real numbers, but not to square root functions.

Q53. Simplify: x^(3/4) divided by x^(1/4)
A x^(1/2)
B x^(3/4)
C x
D x^(3/16)

When dividing powers with the same base, subtract exponents: 3/4 - 1/4 = 2/4 = 1/2. Result: x^(1/2). Choice C = x results from adding exponents (3/4 + 1/4 = 1) instead of subtracting — a common confusion between multiplication and division rules. Choice D = x^(3/16) results from multiplying the exponents (3/4 * 1/4 = 3/16), which applies to a power of a power, not a quotient.

Q54. Simplify: \(\sqrt{x^3}\) for \(x \geq 0\)
A \(x\sqrt{x}\)
B \(x^2\sqrt{x}\)
C \(x^2\)
D \(x^{2/3}\)

Write \(x^3 = x^2 \cdot x\), so \(\sqrt{x^3} = \sqrt{x^2} \cdot \sqrt{x} = x\sqrt{x}\). In rational exponent notation: \(x^{3/2} = x^1 \cdot x^{1/2} = x\sqrt{x}\). Choice B = \(x^2\sqrt{x} = x^{5/2}\), which would equal \(\sqrt{x^5}\). Choice C = \(x^2\) discards the remaining radical entirely. Choice D = \(x^{2/3}\) is the cube root of \(x^2\), not the square root of \(x^3\).

Q55. Solve for x: the cube root of x = -3
A -27
B 27
C -9
D -3

Cube both sides to undo the cube root: x = (-3)^3 = (-3)*(-3)*(-3) = -27. Check: the cube root of -27 = -3. Choice B = 27 results from ignoring the negative sign during cubing. Choice C = -9 confuses cubing with multiplying: (-3) * 3 = -9, but cubing means raising to the third power, not multiplying by 3. Choice D = -3 applies no operation at all.

Q56. Simplify: the fifth root of \((x^{10} y^5)\)
A \(x^2 y\)
B \(x^5 y\)
C \(x y^2\)
D \(x^2 y^5\)

Apply the fifth root to each factor using rational exponents: \((x^{10})^{1/5} \cdot (y^5)^{1/5} = x^{10/5} \cdot y^{5/5} = x^2 y\). Choice B uses \(x^{10/2} = x^5\), applying a square root to \(x\) instead of a fifth root. Choice D leaves \(y^5\) unchanged, forgetting to apply the fifth root to the \(y\) factor.

Q57. Solve for x: \(\sqrt{x^2 + 7} = 4\)
A \(x = 3\) or \(x = -3\)
B \(x = 3\) only
C \(x = 9\) or \(x = -9\)
D \(x = 1\) or \(x = -1\)

Square both sides: \(x^2 + 7 = 16\), so \(x^2 = 9\). Taking the square root of both sides gives \(x = \pm 3\). Both values are valid since \(x^2 + 7 \geq 0\) for all real x. Choice B misses the negative solution. Choice C = \(\pm 9\) results from finding \(x^2 = 9\) but then writing \(x = \pm 9\) instead of taking the square root of 9 to get \(\pm 3\).

Q58. Solve for x: \(x^{2/3} = 9\)
A \(x = 27\) or \(x = -27\)
B \(x = 27\) only
C \(x = 729\) or \(x = -729\)
D \(x = 3\) or \(x = -3\)

Raise both sides to the \(3/2\) power: \(x = \pm 9^{3/2} = \pm(\sqrt{9})^3 = \pm 3^3 = \pm 27\). Both are valid: \((27)^{2/3} = (\sqrt[3]{27})^2 = 3^2 = 9\), and \((-27)^{2/3} = (\sqrt[3]{-27})^2 = (-3)^2 = 9\). Choice B misses the negative solution. Choice C = \(\pm 729\) comes from raising 9 to the 3rd power instead of the \(3/2\). Choice D = \(\pm 3\) stops at \(9^{1/2} = 3\) without completing the cube.

Q59. Expand and simplify: \((x^{1/2} - x^{-1/2})^2\)
A \(x - 2 + x^{-1}\)
B \(x + x^{-1}\)
C \(x - 2 - x^{-1}\)
D \(x^2 - 2 + x^{-2}\)

Use \((a - b)^2 = a^2 - 2ab + b^2\) with \(a = x^{1/2}\) and \(b = x^{-1/2}\). Then \(a^2 = x\), the middle term \(2ab = 2 \cdot x^{1/2} \cdot x^{-1/2} = 2 \cdot x^{1/2 + (-1/2)} = 2 \cdot x^0 = 2\), and \(b^2 = x^{-1}\). Result: \(x - 2 + x^{-1}\). Choice B omits the middle term entirely. Choice C has a sign error on \(x^{-1}\), making it negative instead of positive. Choice D incorrectly squares the outer exponents (\(1/2\) becomes \(2\) and \(-1/2\) becomes \(-2\)) rather than squaring the terms.

Q60. What is the domain of \(f(x) = \sqrt{x^2 - 9}\)?
A \(x \leq -3\) or \(x \geq 3\)
B \(x \geq 3\)
C \(-3 \leq x \leq 3\)
D \(x \geq 9\)

Need \(x^2 - 9 \geq 0\), so \(x^2 \geq 9\), meaning \(|x| \geq 3\). This holds when \(x \leq -3\) or \(x \geq 3\). Choice B correctly identifies one branch but misses \(x \leq -3\) entirely. Choice C is exactly backward — those values make \(x^2 - 9\) negative, which is undefined under a square root. Choice D results from solving \(x^2 \geq 9\) as \(x \geq 9\) without correctly taking the square root of both sides.

Q61. Solve for x: \(\sqrt{x + 3} - \sqrt{x - 2} = 1\)
A \(x = 6\)
B \(x = 3\)
C \(x = 7\)
D \(x = 2\)

Isolate one radical: \(\sqrt{x + 3} = 1 + \sqrt{x - 2}\). Square both sides: \(x + 3 = 1 + 2\sqrt{x - 2} + (x - 2)\), which simplifies to \(x + 3 = x - 1 + 2\sqrt{x - 2}\). Then \(4 = 2\sqrt{x - 2}\), so \(\sqrt{x - 2} = 2\), giving \(x - 2 = 4\) and \(x = 6\). Check: \(\sqrt{9} - \sqrt{4} = 3 - 2 = 1\). Choice C: \(\sqrt{10} - \sqrt{5}\) is approximately \(0.92\), not \(1\). Choice D: \(\sqrt{5} - \sqrt{0} = \sqrt{5}\) is not equal to \(1\).

Q62. For what values of x is \(\sqrt{x^2 - 5x + 6}\) defined?
A \(x \leq 2\) or \(x \geq 3\)
B \(2 \leq x \leq 3\)
C \(x \geq 3\)
D \(x \leq 2\)

Need \(x^2 - 5x + 6 \geq 0\). Factor: \((x - 2)(x - 3) \geq 0\). This product is non-negative when both factors are non-negative (giving \(x \geq 3\)) or both are non-positive (giving \(x \leq 2\)). The domain is \(x \leq 2\) or \(x \geq 3\). Choice B is the interval between the roots where the quadratic is negative, making the radicand negative. Choices C and D each capture only one of the two parts of the domain.

Q63. Simplify: \(\dfrac{x^{3/4} \cdot y^{-1/2}}{x^{-1/4} \cdot y^{1/2}}\)
A \(x / y\)
B \(x^{1/2} / y\)
C \(x \cdot y\)
D \(x^2 / y^2\)

Subtract exponents for each base. For x: \(3/4 - (-1/4) = 3/4 + 1/4 = 1\). For y: \(-1/2 - 1/2 = -1\). Result: \(x^1 \cdot y^{-1} = x/y\). Choice B computes \(x^{3/4 - 1/4} = x^{1/2}\), forgetting to add the double negative for the x denominator exponent. Choice C ignores that the combined y exponent is \(-1\), incorrectly writing \(y^1\) in the numerator.

Q64. If \(f(x) = x^{4/3}\) and \(f(a) = 16\), what are all possible values of a?
A \(a = 8\) or \(a = -8\)
B \(a = 8\) only
C \(a = 4\) or \(a = -4\)
D \(a = 64\) or \(a = -64\)

Solve \(a^{4/3} = 16\) by raising both sides to the \(3/4\) power: \(a = \pm 16^{3/4}\). Compute \(16^{3/4} = (16^{1/4})^3 = 2^3 = 8\). Both values work: \(8^{4/3} = (8^{1/3})^4 = 2^4 = 16\), and \((-8)^{4/3} = ((-8)^{1/3})^4 = (-2)^4 = 16\). Choice B misses the negative solution. Choice D = \(\pm 64\) comes from mistakenly computing \(16^{3/2} = (\sqrt{16})^3 = 4^3 = 64\), using exponent \(3/2\) instead of \(3/4\).

Q65. Simplify: the sixth root of \((x^4)\) times the sixth root of \((x^2)\)
A \(x\)
B \(x^{1/3}\)
C \(x^2\)
D \(x^6\)

Convert to rational exponents and apply the product rule: \(x^{4/6} \cdot x^{2/6}\). Add the exponents: \(4/6 + 2/6 = 6/6 = 1\), giving \(x^1 = x\). Choice B \(= x^{1/3}\) results from subtracting exponents instead of adding: \(4/6 - 2/6 = 2/6 = 1/3\). Choice C \(= x^2\) comes from incorrectly halving the index (using 3 instead of 6), which gives \(x^{4/3} \cdot x^{2/3} = x^2\). Choice D \(= x^6\) comes from multiplying the radicands without applying the sixth root: \(x^4 \cdot x^2 = x^6\).

Q66. What is the value of √49?
A 6
B 8
C ±7
D 7

The principal square root of 49 is 7, because 7² = 49. The √ symbol always refers to the principal (non-negative) root, so √49 = 7, not ±7. The value ±7 is the solution set for x² = 49, which is a different question from evaluating √49.

Q67. Which expression is equivalent to \(x^{1/4}\)?
A \(x/4\)
B \(4x\)
C \(\sqrt[4]{x}\)
D \(x^4\)

By the definition of rational exponents, \(a^{1/n}\) equals the nth root of a. So \(x^{1/4}\) equals \(\sqrt[4]{x}\). The choices \(x/4\) and \(4x\) confuse the exponent \(1/4\) with division or multiplication, and \(x^4\) is a completely different expression.

Q68. What is the value of the cube root of 27?
A 9
B 3
C √3
D 3√3

The cube root of 27 asks: what number cubed equals 27? Since 3³ = 3 × 3 × 3 = 27, the answer is 3. The value 9 is incorrect because 9³ = 729, not 27. The choices √3 and 3√3 are irrational and cannot equal the exact cube root of 27.

Q69. What is the value of 64^(1/2)?
A 32
B 16
C 8
D 6.4

The exponent 1/2 means square root, so 64^(1/2) = √64 = 8, because 8² = 64. A common mistake is dividing 64 by 2 to get 32, but raising to the 1/2 power means taking the square root, not dividing by 2.

Q70. Simplify: √(36x²) for x ≥ 0.
A 6x
B 6x²
C 36x
D 18x

Using the product property of radicals: √(36x²) = √36 · √(x²) = 6 · x = 6x. This simplification is valid because x ≥ 0 ensures √(x²) = x rather than |x|. The result is not 6x² because √(x²) = x, not x².

Q71. What is the domain of f(x) = ⁵√x (the fifth root of x)?
A x ≥ 0
B x > 0
C x ≠ 0
D all real numbers

Odd-index roots, such as cube roots and fifth roots, are defined for all real numbers including negative values. For example, ⁵√(-32) = -2, since (-2)⁵ = -32. Only even-index roots require non-negative radicands. The restriction x ≥ 0 applies to square roots and fourth roots, not fifth roots.

Q72. Simplify: (x^(1/2))^4
A x^(1/8)
B 4x^(1/2)
C
D x^(1/6)

When a power is raised to another power, multiply the exponents: (x^(1/2))^4 = x^(1/2 · 4) = x^(4/2) = x². Treating 4 as a coefficient to get 4x^(1/2) is wrong — the 4 is an exponent applied to the whole expression, not a multiplier. Adding exponents to get x^(9/2) is the rule for multiplying like bases, not raising a power to a power.

Q73. Simplify: √50
A 10√5
B 5√2
C 25√2
D 5√10

Factor 50 as 25 · 2, where 25 is a perfect square: √50 = √(25 · 2) = √25 · √2 = 5√2. The choice 25√2 is incorrect because (25√2)² = 1250 ≠ 50. The choice 10√5 is also wrong: (10√5)² = 500 ≠ 50.

Q74. Solve for x: √(x + 5) = 3
A x = 14
B x = 4
C x = -2
D x = ±4

Square both sides to eliminate the radical: x + 5 = 9. Subtract 5: x = 4. Check: √(4 + 5) = √9 = 3 ✓. The choice x = 14 results from adding 5 to 9 instead of subtracting it. The choice x = -2 comes from incorrectly subtracting 3 from 5 instead of solving the squared equation properly.

Q75. What is the domain of f(x) = √(2x - 6)?
A x ≥ 6
B x > 3
C x ≥ -3
D x ≥ 3

For a square root to produce a real number, the radicand must be ≥ 0. Set 2x - 6 ≥ 0 and solve: 2x ≥ 6, so x ≥ 3. The value x = 3 is included because √0 = 0 is defined. The choice x > 3 incorrectly excludes x = 3. The choice x ≥ 6 comes from only dividing one side of the inequality by 2.

Q76. What is the value of 16^(3/4)?
A 12
B 4
C 8
D 6

Interpret the rational exponent as a root then a power: 16^(3/4) = (16^(1/4))³ = (⁴√16)³. First find the fourth root: ⁴√16 = 2, since 2⁴ = 16. Then cube: 2³ = 8. The choice 4 is just the fourth root without cubing. The choice 12 comes from multiplying 3 by 4 instead of applying the exponent correctly.

Q77. Simplify: (x^(2/3))^(3/2) for x ≥ 0.
A x^(4/9)
B x^(1/2)
C x^(3/2)
D x

When raising a power to a power, multiply the exponents: (x^(2/3))^(3/2) = x^(2/3 · 3/2) = x^(6/6) = x¹ = x. The exponents 2/3 and 3/2 are reciprocals, so their product is 1. The choice x^(4/9) incorrectly multiplies only the numerators together and denominators together without recognizing that 2/3 · 3/2 simplifies to 1.

Q78. Simplify: √12 + √27
A 5√3
B 3√13
C √39
D 6√3

Simplify each radical separately: √12 = √(4 · 3) = 2√3, and √27 = √(9 · 3) = 3√3. Since both terms share the same radicand, add the coefficients: 2√3 + 3√3 = 5√3. The choice √39 incorrectly adds the radicands (12 + 27 = 39). The choice 6√3 incorrectly multiplies the coefficients 2 and 3 instead of adding them.

Q79. Solve for x: the cube root of (2x - 1) = 3
A x = 1
B x = 28
C x = 14
D x = 13

Cube both sides to eliminate the cube root: 2x - 1 = 3³ = 27. Add 1: 2x = 28. Divide by 2: x = 14. Check: the cube root of (28 - 1) = the cube root of 27 = 3 ✓. The choice x = 1 results from using 3 instead of 27 (forgetting to cube). The choice x = 28 stops one step early, before dividing by 2.

Q80. What is the range of f(x) = √(x + 4) + 1?
A y ≥ -4
B y ≥ 5
C all real numbers
D y ≥ 1

The expression √(x + 4) has a minimum value of 0 (when x = -4), so √(x + 4) ≥ 0 for all x in the domain. Adding 1 shifts every output up by 1: √(x + 4) + 1 ≥ 1. Therefore the range is y ≥ 1. The choice y ≥ -4 confuses the domain bound with the range. The choice y ≥ 5 incorrectly computes the range minimum as 4 + 1 = 5.

Q81. Multiply and simplify: √(2x) · √(8x), where x ≥ 0.
A 16x
B 4x²
C 4√x
D 4x

Use the product property of radicals: √(2x) · √(8x) = √(2x · 8x) = √(16x²). Then simplify: √16 · √(x²) = 4 · x = 4x (since x ≥ 0). The choice 16x is incorrect because √(16x²) ≠ 16x — only the square root of 16 is taken. The choice 4x² incorrectly keeps x² instead of taking its square root.

Q82. Which expression is equivalent to \(x^{2/5}\)?
A \(\sqrt[5]{x^2}\)
B \(2x^{1/5}\)
C \(\sqrt{x^5}\)
D \(x^{10}\)

By the rule \(a^{m/n} = \sqrt[n]{a^m}\), the expression \(x^{2/5}\) equals \(\sqrt[5]{x^2}\). Equivalently, \(x^{2/5} = (x^{1/5})^2\), meaning the fifth root of x, then squared. The choice \(\sqrt{x^5}\) equals \(x^{5/2}\), not \(x^{2/5}\). The choice \(2x^{1/5}\) treats the numerator 2 as a coefficient instead of an exponent.

Q83. What is the value of (-8)^(2/3)?
A -4
B 16
C 4
D not a real number

Interpret the rational exponent step by step: (-8)^(2/3) = ((-8)^(1/3))² = (cube root of -8)². The cube root of -8 is -2, since (-2)³ = -8. Then (-2)² = 4. The result is positive because squaring any real number yields a non-negative value. The choice 'not a real number' is incorrect — cube roots of negative numbers are real, unlike square roots of negative numbers.

Q84. Solve for x: √(3x + 4) + 2 = x. Which value or values are valid solutions?
A x = 0 only
B no solution
C x = 7 only
D x = 0 and x = 7

Isolate the radical: √(3x + 4) = x - 2. For the square root to equal x - 2, we need x - 2 ≥ 0, so x ≥ 2. Square both sides: 3x + 4 = x² - 4x + 4, giving x² - 7x = 0, so x(x - 7) = 0. The candidates are x = 0 and x = 7. Since x = 0 fails x ≥ 2 (check: √4 + 2 = 4 ≠ 0), it is extraneous. Only x = 7 is valid: √25 + 2 = 7 ✓.

Q85. If f(x) = x^(2/3), what is f(f(x))?
A x^(4/3)
B x^(4/9)
C x^(1/3)
D x^(2/9)

To find f(f(x)), substitute f(x) into f: f(f(x)) = f(x^(2/3)) = (x^(2/3))^(2/3) = x^(2/3 · 2/3) = x^(4/9). A common mistake is to add the exponents and get x^(4/3), but that would be f(x) · f(x) = [f(x)]², not f composed with f. Composition means applying the exponent rule for power of a power, which multiplies exponents.

Q86. Solve for x: \(x^{3/2} = 27\), where \(x \geq 0\).
A \(x = 3\)
B \(x = 18\)
C \(x = 81\)
D \(x = 9\)

Raise both sides to the power \(2/3\), the reciprocal of \(3/2\): \(x = 27^{2/3} = (27^{1/3})^2 = 3^2 = 9\). Verify: \(9^{3/2} = (9^{1/2})^3 = 3^3 = 27\) ✓. The choice \(x = 3\) is the cube root of \(27\), which solves \(x^3 = 27\), not \(x^{3/2} = 27\). The choice \(x = 81\) comes from incorrectly squaring \(27\) (\(27^2 = 729 \neq 27^{2/3}\)).

Q87. What is the domain of f(x) = √(x² - 4x + 3)?
A 1 ≤ x ≤ 3
B x ≤ 1 or x ≥ 3
C x ≥ 3
D all real numbers

Set the radicand ≥ 0: x² - 4x + 3 ≥ 0. Factor: (x - 1)(x - 3) ≥ 0. This product is non-negative when both factors are non-negative (x ≥ 3) or both are non-positive (x ≤ 1). So the domain is x ≤ 1 or x ≥ 3. Choice A (1 ≤ x ≤ 3) is actually where the radicand is negative — for example, at x = 2: 4 - 8 + 3 = -1 < 0.

Q88. Rationalize the denominator: 3 / (√5 - √2)
A √5 + √2
B 3(√5 + √2) / 7
C (√5 + √2) / 3
D 3(√5 - √2) / 3

Multiply numerator and denominator by the conjugate (√5 + √2): [3(√5 + √2)] / [(√5 - √2)(√5 + √2)] = [3(√5 + √2)] / (5 - 2) = [3(√5 + √2)] / 3 = √5 + √2. Choice B uses 7 in the denominator, which results from incorrectly computing (√5)² + (√2)² = 7 instead of the difference of squares (√5)² - (√2)² = 3.

Q89. Solve for x: √(x + 1) = x - 1. Which value or values are valid solutions?
A x = 0 and x = 3
B x = 3 only
C x = 0 only
D no real solution

Square both sides: x + 1 = (x - 1)² = x² - 2x + 1. Rearranging: 0 = x² - 3x = x(x - 3), giving x = 0 or x = 3. Check x = 0: √1 = 0 - 1 → 1 = -1, which is false — x = 0 is extraneous. Check x = 3: √4 = 3 - 1 → 2 = 2 ✓. Only x = 3 is valid. Extraneous solutions arise because squaring both sides can introduce values that satisfy the squared equation but not the original.

Q90. Simplify: (a^(1/2) · b^(3/4))^4 / (a · b²)
A a²b
B a³b²
C ab
D ab³

Expand the numerator by distributing the outer exponent: (a^(1/2))^4 · (b^(3/4))^4 = a^(1/2 · 4) · b^(3/4 · 4) = a² · b³. Now divide by (a · b²) using the quotient rule for exponents: a² / a = a^(2-1) = a, and b³ / b² = b^(3-2) = b. The result is a · b = ab. The choice a²b omits dividing a², and ab³ omits dividing b³.

Q91. What is the principal square root of 144?
A 12
B -12
C 72
D 14.4

The principal square root of 144 is 12 because 12^2 = 144. The principal square root is always the non-negative root by definition, so -12 is excluded. 72 is simply 144/2, and 14.4 is a rough decimal estimate — neither equals the exact principal root.

Q92. What is the value of the cube root of -125?
A -5
B 5
C -25
D Undefined

The cube root of -125 is -5 because (-5)^3 = -125. Unlike square roots, cube roots (and all odd-index roots) are defined for negative numbers. The result is negative when the radicand is negative. -25 is incorrect because (-25)^3 = -15625, not -125.

Q93. Which expression is equivalent to \(\sqrt[5]{x^3}\), for \(x \geq 0\)?
A \(x^{3/5}\)
B \(x^{5/3}\)
C \(x^{2/5}\)
D \(x^{8/5}\)

The nth root of \(x^m\) equals \(x^{m/n}\), where the power becomes the numerator and the root index becomes the denominator. So \(\sqrt[5]{x^3}\) equals \(x^{3/5}\). Choosing \(x^{5/3}\) reverses the numerator and denominator, a common error.

Q94. What is the value of 25^(1/2)?
A 5
B 12.5
C 625
D 50

A rational exponent of 1/2 means square root: 25^(1/2) = the square root of 25 = 5. The value 12.5 comes from dividing 25 by 2, which confuses division with taking a root. 625 = 25^2 and 50 = 25 times 2 — both use multiplication or squaring instead.

Q95. Simplify: the square root of 72
A 6 times the square root of 2
B 8 times the square root of 2
C 6 times the square root of 3
D 36 times the square root of 2

Factor out the largest perfect square: 72 = 36 times 2, so the square root of 72 = the square root of 36 times the square root of 2 = 6 times the square root of 2. Choosing 8 times the square root of 2 is wrong because 8^2 times 2 = 128, not 72. The correct perfect square factor is 36, not 4 or 9.

Q96. What is the index of the radical expression: the fourth root of x?
A 4
B 2
C 1/4
D x

The index of a radical is the small number placed in the notch of the radical symbol indicating which root to take. For the fourth root of x, the index is 4. When no index is written on a radical, the index is assumed to be 2 (a square root). The index is not the same as the exponent 1/4, although they are related.

Q97. What is the value of 27^(1/3)?
A 3
B 9
C 81
D 1/3

27^(1/3) means the cube root of 27. Since 3^3 = 27, the answer is 3. The value 9 is the square root of 81, not the cube root of 27. Raising to the 1/3 power is equivalent to finding the cube root, not dividing by 3.

Q98. For the function f(x) = the square root of (x minus 3), what is the smallest value in its domain?
A 3
B -3
C 0
D 9

The radicand of a square root must be non-negative: x minus 3 is greater than or equal to 0, which gives x is greater than or equal to 3. The smallest value in the domain is x = 3, at which point f(3) = the square root of 0 = 0. Choosing x = -3 would make the radicand -6, which is negative and not allowed.

Q99. Solve for x: the square root of (2x + 3) = 5
A 11
B 5.5
C 1
D 22

Square both sides to eliminate the radical: 2x + 3 = 25. Subtract 3: 2x = 22. Divide by 2: x = 11. Verify: the square root of (22 + 3) = the square root of 25 = 5. The value 5.5 likely comes from dividing 11 by 2 prematurely. Always verify solutions after squaring, as extraneous solutions can appear.

Q100. Simplify: \((8x^6)^{2/3}\) for \(x \geq 0\)
A \(4x^4\)
B \(8x^4\)
C \(4x^9\)
D \(2x^4\)

Apply the exponent \(2/3\) to each factor separately. \(8^{2/3} = (\sqrt[3]{8})^2 = 2^2 = 4\). For \(x^6\): \((x^6)^{2/3} = x^{6 \times 2/3} = x^4\). So the result is \(4x^4\). Choosing \(8x^4\) keeps \(8\) unchanged, forgetting to apply the rational exponent to the coefficient.

Q101. Simplify: the square root of 18 minus the square root of 8
A the square root of 2
B the square root of 10
C 2 times the square root of 2
D 5 times the square root of 2

First simplify each radical: the square root of 18 = 3 times the square root of 2, and the square root of 8 = 2 times the square root of 2. Subtract like terms: 3 times the square root of 2 minus 2 times the square root of 2 = 1 times the square root of 2. A common error is subtracting the radicands directly to get the square root of 10, but radicals can only be combined when their radicands match.

Q102. What is the domain of f(x) = the square root of (7 minus 2x)?
A x is less than or equal to 7/2
B x is greater than or equal to 7/2
C x is less than or equal to 7
D x is greater than or equal to negative 7/2

Set the radicand greater than or equal to zero: 7 minus 2x is greater than or equal to 0. Subtract 7: negative 2x is greater than or equal to negative 7. Divide by negative 2 and flip the inequality: x is less than or equal to 7/2. Forgetting to reverse the inequality sign when dividing by a negative number leads to the incorrect answer x greater than or equal to 7/2.

Q103. Solve for x: the cube root of (x minus 2) = negative 3
A -25
B -1
C 25
D -29

Cube both sides: x minus 2 = (-3)^3 = -27. Add 2 to both sides: x = -25. Verify: the cube root of (-25 minus 2) = the cube root of (-27) = -3. Since cube roots are defined for negative numbers, this equation has a valid real solution. x = -1 comes from ignoring the cube and just solving x minus 2 = -3.

Q104. Simplify: x^(1/3) times x^(1/2) for x greater than or equal to 0. Write your answer with a single rational exponent.
A x^(5/6)
B x^(1/6)
C x^(2/3)
D x^(3/5)

When multiplying powers with the same base, add the exponents: 1/3 plus 1/2. Find a common denominator: 2/6 plus 3/6 = 5/6. So x^(1/3) times x^(1/2) = x^(5/6). The choice x^(1/6) comes from multiplying the exponents (1/3 times 1/2) instead of adding them, which would apply only when raising a power to a power.

Q105. Which expression is equivalent to \(x^{5/3}\) for \(x \geq 0\)?
A \((\sqrt[3]{x})^5\)
B \((\sqrt{x})^5\)
C \(\sqrt[5]{x^3}\)
D \(\sqrt[3]{x^{5/3}}\)

In the rational exponent \(x^{m/n}\), the denominator \(n\) is the root index and the numerator \(m\) is the power. So \(x^{5/3} = (x^{1/3})^5 = (\sqrt[3]{x})^5\). The choice \((\sqrt{x})^5\) equals \(x^{5/2}\), not \(x^{5/3}\). The fifth root of \(x^3\) equals \(x^{3/5}\), which swaps the numerator and denominator.

Q106. Multiply and simplify: 2 times the square root of 5 times 3 times the square root of 15
A 30 times the square root of 3
B 6 times the square root of 75
C 6 times the square root of 20
D 15 times the square root of 6

Multiply the coefficients and the radicands separately: (2 times 3) times the square root of (5 times 15) = 6 times the square root of 75. Then simplify: the square root of 75 = the square root of (25 times 3) = 5 times the square root of 3. So the final answer is 6 times 5 times the square root of 3 = 30 times the square root of 3. The choice 6 times the square root of 75 is partially correct but not fully simplified.

Q107. What is the value of 32^(3/5)?
A 8
B 4
C 16
D 6

Rewrite using roots and powers: 32^(3/5) = (32^(1/5))^3 = (the fifth root of 32)^3. Since 2^5 = 32, the fifth root of 32 is 2. Then 2^3 = 8. The choice 4 corresponds to 32^(2/5) = 2^2, using the wrong numerator. The choice 16 corresponds to 2^4, adding one too many to the exponent.

Q108. Solve for x: the square root of (x + 3) = the square root of (2x minus 5). Which value is a valid solution?
A 8
B -8
C 2
D No real solution exists

Square both sides: x + 3 = 2x minus 5. Subtract x from both sides and add 5: 8 = x. Verify: the square root of (8 + 3) = the square root of 11, and the square root of (2 times 8 minus 5) = the square root of 11. Both sides match, so x = 8 is valid. x = -8 makes the radicands negative, so it is not in the domain. Always verify solutions after squaring.

Q109. Solve for x in the equation x^(2/3) = 4, where x is a real number. Which answer lists all solutions?
A x = 8 or x = -8
B x = 8 only
C x = 6 or x = -6
D x = 64

Raise both sides to the 3/2 power: x = plus or minus 4^(3/2) = plus or minus (the square root of 4)^3 = plus or minus 2^3 = plus or minus 8. Both values are valid because the exponent 2/3 includes an even power: 8^(2/3) = (cube root of 8)^2 = 4 and (-8)^(2/3) = (cube root of -8)^2 = (-2)^2 = 4. Selecting only x = 8 misses the negative solution.

Q110. What is the range of f(x) = negative square root of (x + 1) plus 4?
A y is less than or equal to 4
B y is greater than or equal to 4
C y is less than or equal to negative 4
D all real numbers

The parent function square root of x has range y greater than or equal to 0. The negative sign reflects it vertically, giving negative square root of x with range y less than or equal to 0. Shifting up by 4 gives range y less than or equal to 4. The maximum value is 4, achieved when x = -1 (making the square root equal to 0). As x increases, the output decreases without bound. Choosing y greater than or equal to 4 ignores the reflection.

Q111. Simplify: \((x^{1/2} \times y^{2/3})^6\), for \(x \geq 0\) and \(y \geq 0\)
A \(x^3 \times y^4\)
B \(x^3 \times y^3\)
C \(x^6 \times y^4\)
D \(x^3 \times y^{4/3}\)

Apply the outer exponent \(6\) to each factor using the power rule (multiply exponents): \((x^{1/2})^6 = x^{6/2} = x^3\), and \((y^{2/3})^6 = y^{12/3} = y^4\). The result is \(x^3 \times y^4\). Choosing \(x^3 \times y^3\) applies the exponent \(6\) incorrectly to \(y\), treating \(2/3\) as if the \(6\) cancels only the \(3\) but ignores the numerator \(2\).

Q112. Solve for x: the square root of (x + 5) plus the square root of x = 5
A 4
B 0
C 9
D 25

Isolate one radical: the square root of (x + 5) = 5 minus the square root of x. Square both sides: x + 5 = 25 minus 10 times the square root of x plus x. Simplify: 5 = 25 minus 10 times the square root of x, so 10 times the square root of x = 20, giving the square root of x = 2, and x = 4. Verify: the square root of 9 plus the square root of 4 = 3 plus 2 = 5. The choice x = 0 gives the square root of 5 plus 0, which does not equal 5.

Q113. Find all real solutions to x^(4/3) = 16
A x = 8 or x = -8
B x = 8 only
C x = 12
D x = 64

Raise both sides to the 3/4 power: x = plus or minus 16^(3/4) = plus or minus (the fourth root of 16)^3 = plus or minus 2^3 = plus or minus 8. Both are valid: 8^(4/3) = (cube root of 8)^4 = 2^4 = 16, and (-8)^(4/3) = (cube root of -8)^4 = (-2)^4 = 16. The even numerator in the final power makes both signs valid. x = 64 comes from incorrectly squaring 16 then taking a root.

Q114. Solve for x: the square root of (3x + 1) minus the square root of (x minus 1) = 2. Which answer lists all valid solutions?
A x = 1 or x = 5
B x = 5 only
C x = 1 only
D x = 3

Isolate one radical: the square root of (3x + 1) = 2 plus the square root of (x minus 1). Square both sides: 3x + 1 = 4 plus 4 times the square root of (x minus 1) plus x minus 1. Simplify: 2x minus 2 = 4 times the square root of (x minus 1), or x minus 1 = 2 times the square root of (x minus 1). Let u = the square root of (x minus 1): u^2 = 2u, so u(u minus 2) = 0, giving u = 0 or u = 2, meaning x = 1 or x = 5. Both solutions check out when substituted back.

Q115. If \(g(x) = x^{3/2}\) for \(x \geq 0\), what is the inverse function \(g^{-1}(x)\)?
A \(x^{2/3}\)
B \(x^{1/3}\)
C \(x^{-3/2}\)
D \(x^3\)

To find the inverse, replace \(g(x)\) with \(y\) and swap \(x\) and \(y\): \(x = y^{3/2}\). Raise both sides to the \(2/3\) power (the reciprocal of \(3/2\)): \(x^{2/3} = y\). The inverse is \(g^{-1}(x) = x^{2/3}\). The exponent of the inverse is the reciprocal of the original exponent: \(3/2\) and \(2/3\) are reciprocals. Choosing \(x^{-3/2}\) gives the reciprocal of the function, not the inverse function.

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Quick summary

This unit covers nth roots, rational exponents and solving radical equations — essential concepts for Algebra 2. Use our interactive study games to test your understanding, or review questions in traditional format below.

Key concepts
  • Nth roots
  • Rational exponents
  • Solving radical equations
What you need to know

Key Concepts Breakdown

1 Nth Roots

Students must understand how to evaluate and simplify nth roots, including square roots, cube roots, and fourth roots. They need to know when an nth root is defined in the real number system — even-index roots require non-negative radicands, while odd-index roots allow any real number. Simplifying radicals by factoring out perfect nth powers is a core tested skill.

Key Points

  • √(a) is defined only when a ≥ 0; ∛(a) is defined for all real a
  • To simplify, factor the radicand and pull out perfect nth powers: ∛(54) = ∛(27·2) = 3∛(2)
  • The nth root of a product: ⁿ√(ab) = ⁿ√(a) · ⁿ√(b)
  • ⁴√(x⁸) = x² because (x²)⁴ = x⁸ — match the index to the exponent
Example

Simplify: ⁴√(80x⁵)

Explanation

Factor 80 as 16·5, so ⁴√(80x⁵) = ⁴√(16 · 5 · x⁴ · x). Pull out the perfect fourth powers: ⁴√(16) = 2 and ⁴√(x⁴) = x. The result is 2x·⁴√(5x).

2 Rational Exponents

Students must be able to convert between radical notation and rational exponent notation, and apply exponent rules to expressions with fractional exponents. The definition a^(m/n) = (ⁿ√a)^m = ⁿ√(aᵐ) must be memorized and applied fluently. Simplifying and evaluating expressions like 8^(2/3) or 27^(-1/3) are standard exam questions.

Key Points

  • a^(1/n) = ⁿ√(a); a^(m/n) = (ⁿ√a)^m
  • Negative rational exponents: a^(-m/n) = 1 / a^(m/n)
  • All standard exponent rules apply: product rule, quotient rule, power rule
  • To evaluate 8^(2/3): take the cube root first (= 2), then square (= 4) — easier than cubing first
Example

Evaluate: 32^(3/5)

Explanation

Rewrite as (⁵√32)³. The fifth root of 32 is 2, since 2⁵ = 32. Then 2³ = 8, so 32^(3/5) = 8.

3 Solving Radical Equations

Students must solve equations containing radical expressions by isolating the radical and raising both sides to the appropriate power to eliminate it. The most critical skill is checking for extraneous solutions — squaring both sides can introduce solutions that do not satisfy the original equation. Every solution must be substituted back into the original equation.

Key Points

  • Isolate the radical on one side before raising both sides to a power
  • Square both sides to eliminate a square root; cube both sides for a cube root
  • Always check answers in the ORIGINAL equation — extraneous solutions are a common exam trap
  • If two radicals are present, isolate one, raise to a power, then repeat for the second
Example

Solve: √(2x + 3) = x − 1

Explanation

Square both sides to get 2x + 3 = (x − 1)² = x² − 2x + 1. Rearranging gives x² − 4x − 2 = 0, wait — rearrange: 0 = x² − 4x − 2, solving via quadratic formula gives x = (4 ± √24)/2 = 2 ± √6. Check both in the original: x = 2 + √6 ≈ 4.45 works; x = 2 − √6 ≈ −0.45 gives a negative right side while the left side is non-negative, so it is extraneous. The only solution is x = 2 + √6.

FAQ

Questions, answered.

What is Radical Functions?

Radical Functions is Unit 6 of Algebra 2, covering nth roots, rational exponents and solving radical equations.

How to study for Algebra 2 Unit 6?

Start with the Quick Summary above, review the Key Concepts, then test yourself with our interactive study games. Aim for 80%+ accuracy before moving on.

How many questions are in this unit?

This unit has 115 review questions, each with a written explanation, playable across 5 different game modes or readable in plain-text mode.