Question 766994
Find the equation in standard form of the parabola with directrix x = 3 and vertex (1, -2)
Equation is that of a parabola which open leftward:
Its basic equation: (y-k)^2=-4p(x-h), (h,k)=(x,y) coordinates of the vertex.
For given parabola:
vertex:(1,-2)
axis of symmetry: y=-2
p=3 (distance from vertex to directrix on the axis of symmetry)
4p=12
Equation of given parabola: (y+2)^2=-12(x-1)