ini gimana kak?? tong jawab ya kak

melewati (0,9)

y = ax² + bx + c
9 = 0 + 0 + c
c = 9

titik balik (-3 ,0)

-3 = -b/2a
-6a = -b
b = 6a

y = ax² + bx + 9
y = ax² + 6ax + 9
0 = a(-3)² + 6a(-3) + 9
0 = 9a - 18a + 9
0 = -9a + 9
-9a = -9
a = 1

b = 6(1) = 6

pers : y = x²+6x+9