Math
Point-slope form.
Definition
A form of a linear equation that uses a known point (x₁, y₁) and the slope m to write the equation of a line. It is especially useful when you know the slope and one point but not the y-intercept.
Examples
Real-world.
- 1 A line through (2, 3) with slope 4: y - 3 = 4(x - 2)
- 2 Writing the equation of a tangent line in calculus
- 3 Finding a line through (1, -5) with slope -2: y + 5 = -2(x - 1)
Key Fact
y - y₁ = m(x - x₁)