parabola


Find the eqn: of the parabola whose focus is (3,-4) & directrix is x-y+5=0 ?
help me

Use the distance formula and the formula for the distance from a point to a line.

\sqrt{(x-3)^{2}+(x+4)^{2}}=\frac{|x-y+5|}{\sqrt{2}}

Square both sides, then expand and simplify:

(x-3)^{2}+(x+4)^{2}-\left(\frac{x-y+5}{\sqrt{2}}\right)^{2}=0