Jawab:

Penjelasan dengan langkah-langkah:

persamaan fungsi kuadrat

titik puncak ( -3 , 2 )

titik potong ( 0,1 )

grafik kebawah a < 0

y = a(x-p)^2 + q

1 = a ( 0 - (-3) )^2 + 2

1 = a ( 3 )^2 + 2

1 = 9a + 2

9a = -1

a = -1/9

titik puncak

-b/2a = -3

-b/2(-1/9) = -3

-b = -3. -2/9

b = -2/3

-D/4a = 2

- D/4.(-1/9) = 2

- D= 2 . -4/9

D = 8/9

b^2 - 4ac = 8/9

(-2/3)^2 - 4(-1/9)c = 8/9

(4/9) + (4/9)c = 8/9

4/9c = 8/9 - 4/9

4/9 c = 4/9

c = 4/9 x 9/4

c = 1

maka persamaan kuadratnya menjadi

f(x) = -1/9x^2 - 2/3 x + 1