Math
Vertex form.
Definition
Vertex form is a way of writing a quadratic function as y = a(x − h)² + k, where (h, k) is the vertex of the parabola. This form makes it easy to identify the vertex, axis of symmetry, and direction of opening directly from the equation.
Examples
Real-world.
- 1 y = 2(x − 3)² + 5 has vertex at (3, 5) and opens upward
- 2 y = −(x + 1)² − 4 has vertex at (−1, −4) and opens downward
- 3 Converting y = x² − 6x + 11 to vertex form gives y = (x − 3)² + 2
Key Fact
y = a(x − h)² + k; vertex is (h, k), axis of symmetry is x = h