Question

What is the standard form of the equation of the parabola with a directrix at x=7 and a focus at (12,-15)?

Answer 1

Equation of Parabola is `x=1/10*(y+15)^2+9.5`

Explanation:

Vertex is at mid-point between vertex and directrix. So vertex is at `(9.5, -15)` The equation of Parabola is `x = a*(y+15)^2+9.5` now `a= 1/(4*d)` where d is distance between vertex and focus `:. a =1/(4*2.5) or a=1/10` So Equation of Parabola is `x=1/10*(y+15)^2+9.5` graph{x=1/10*(y+15)^2+9.5 [-80, 80, -40, 40]} [Answer]