persamaan parabola dgn fokus (5,-2) dgn puncak (1,-2) berbentuk

Puncak (a,b) ==> (1,-2)
Fokus(a+p,b) ==> (5,-2)
a+p = 5
1+p = 5
     p = 5-1
     p = 4
persamaan parabola:
(y-b)² = 4p(x-a)
(y+2)² = 16(x-1)
y²+4y+4 = 16x-16
y²+4y-16x+20 = 0