2.1 Quadratic forms and graph features

Ideas in this lesson

Vertex form

The form a(x − h)² + k reveals the vertex and direction of opening.

Intercept form

The form a(x − r)(x − s) reveals zeros r and s. Their midpoint is the axis of symmetry.

Standard form

For ax² + bx + c, the vertex input is −b/(2a). Substitute it to find the output.