Question

Write an equation of the parabola with vertex (2,2) and directrix x=4.

Answer 1

\[(x-h)^2 = 4a(y-k) \] is the equation for the parabola with vertex (h,k).
So what are h and k in this case?

Directrix is always y= a - k units. Use this to find value of a. Then sub a, h, and k into the general equation shown above.