What is the equation in standard form of the parabola with a focus at (-14,-1) and a directrix of y= -32?

1 Answer
Dec 30, 2015

62y = x^2 +28x - 86062y=x2+28x860

Explanation:

The equation of the parabola can be written as 4p(y- k)= (x-h)^24p(yk)=(xh)2 from which the vertex is (h,k)(h,k) and pp is the distance from the vertex to the focus (or the directrix since the directrix is an equal distance the other side of the vertex).

The focus and directrix are (-1 - (-32))(1(32)) units apart and p is therefore 1/2(31) = 31/212(31)=312
The vertex is at (-14,-1-31/2) = (-14,-33/2)(14,1312)=(14,332)
The equation is therefore 4*31/2 (y+33/2) = (x+14)^24312(y+332)=(x+14)2
62y +32*33 = x^2 +28x +14^262y+3233=x2+28x+142
62y = x^2 +28x +196 - 105662y=x2+28x+1961056
62y = x^2 +28x - 86062y=x2+28x860