ada yang bisa bantu?

x1 = -2, x2 = 1 (x1 dan x2 adalah titik potong terhadap sumbu x)
Titik potong terhadap sumbu y = (x, y) = (0, 1)
Persamaan fungsi kuadrat :
y = a (x - x1)(x - x2)
1 = a (0 + 2)(0 - 1)
1 = a . 2 . (-1)
1 = -2a
a = -1/2
y = a(x - x1)(x - x2)
y = -1/2 (x + 2)(x - 1)
y = -1/2 (x^2 + x - 2)
y = -1/2 x^2 - 1/2 x + 1

^ = pangkat

[tex]\displaystyle y=ax^2+bx+c\\1=a(0)^2+b(0)+c\\1=c\\\\0=ax^2+bx+1\\\\x_1x_2=\frac ca\\-2\cdot1=\frac 1a\\a=-\frac12\\\\x_1+x_2=-\frac ba\\-2+1=-\frac b{-\frac12}\\-1=2b\\-\frac12=b\\\\y=ax^2+bx+c\\\boxed{\boxed{y=-\frac12x^2-\frac12x+1}}[/tex]