Jawabanmu

2014-05-07T17:32:19+07:00
F(x)= 2x² - 7x² + 8x = -5x² + 8x
a) f¹(x) = -10x + 8
b)
naik --> f'(x) > 0 --> -10x +8 > 0 --> -10x>-8 --> x<4/5
turun --> f'(x) < 0 --> -10x +8 < 0 --> -10x<-8 --> x>4/5
c) stationer :
f'(x) = 0 --> -10x +8 = 0 --> -10x = -8 --> x=4/5