Question

Identify th equation of the parabola whose focus is at (5,-1) and whose directrix is x=3

I don't see any examples of this kind of problem.

Answer 1

is this right?

(x-5)^2+(y+1)^2=(x-3)^2
so
-10x+25+y^2+2y+1=-6x+9
4x=y^2+2y+17