Question

Write the standard form equation of the parabola that passes through (20,−40),if the vertex at the origin and the axis of symmetry is vertical.

Answer 1

Answer:

y = -0.1x^2

Step-by-step explanation:

Start out with vertex form

y = a(x - h)^2 + k

The vertex at the origin

Therefor (h, k) = (0, 0)

y = ax^2

use point (20, -40) to find a

-40 = a(20^2)

-40 = a(400)

Divide both sides by

400

-0.1 = a

Therefor

y = -0.1x^2

This is standard form with a = -.01 and both b and c equal to zero