Question

.1.kordinat titik puncak dari parabola y=2x+8x-9=..

2.nilai fungsi f(x)=-3xkuadrat+2x+4pada x=-2..adlh
3. diketahui kubus abcd /efgh. dg pj rusuk akar 6 cm. jarak. titik a ke garis cf adalah..

Answer 1

1. y =  2x² + 8x - 9
 xp = -b/2a
= -8/2(2)
= -2
x = 2 ⇒ y = 2(4) + 8(-2) - 9
= -17
koordinatnya: (-17, - 2)

2. f(x) = -3x² + 2x + 4
saat x = 2 ⇒ f(2) = -3(4) + 2(2) + 4 = -4 

Answer 2

1.
y = 2x² + 8x - 9 
y' = 4x + 8 = 0
x = -2
y = 2(-2)² + 8(-2) - 9 = 8 - 16 - 9 = -17
Puncak (-2, -17)
2.
f(x) = -3x² + 2x + 4
f(-2) = -3(-2)² + 2(-2) + 4 = -12 - 4 + 4 = -12