f(x)=x2+bx+7 yg titik puncaknya memiliki absis 4, maka titik koordinatnya

jawab

f(x)  = x² + bx + 7
a = 1
b = b
c = 7
absis 4 → x = 4

titkk puncak  (x, y)
x = - b/2a 
x = 4
- b/2a = 4
-b/2(1) = 4
-b = 2(4)
b = - 8
f(x) = x² - 8x + 7
f(4) = 4² - 8(4) + 7
f(4) = -9
titik puncak (x,y)  = (4,  - 9)