Fungsi Kuadrat

f(x) = ax² + bx + c

f(x) = -x² - 2x + 24

a = -1

b = -2

c = 24

◆ titik potong dg sumbu y → x = 0

f(0) = y = c = 24

Titik potong dg sumbu y → (0,24)

◆ titik potong dg sumbu x → y = 0

y = 0

-x² - 2x + 24 = 0)

(-x + 4)(x + 6) = 0

x = 4 atau x = -6

Titik potong dg sumbu x → (4,0) dan (-6,0)

◆ Persamaan sumbu simetri xp = -b/2a

xp = -(-2)/2(-1)

xp = -1

◆ Titik puncak

xp = -1

yp = f(-1) = -(-1)² - 2(-1) + 24

yp = 25

Titik puncak (xp,yp) = (-1,25)

Pernyataan yg benar : Opsi D

(iii) dan (iv)