Question

find equation of parabola having focus at (5,0) and directrix x + 5 = 0

Answer 1

Let the equation of the parabola : y² = 4ax

Focus : S = (a , 0 ) = (5,0) …. given ∴ a = 5 

Directrix : 

x + a = 0 

x + 5 = 0 ……. Given ∴ a = 5

Hence equation of the parabola : 

y² = 4ax 

y² = 4(5)x 

y² = 20x