kk tolong tunjukkan cara nyari nya

Jawabannya a
Maaf kalo salah

f(x) = (2/3)x³ - (1/2)x² - 3x + 1/6

g(x) = f(1 - x)
g(x) = (2/3)(1 - x)³ - (1/2)(1 - x)² - 3(1 - x) + 1/6

g'(x) = (6/3)(1 - x)² . -1 - (2/2)(1 - x) . -1 - 3(-1)
g'(x) = -2(1 - 2x + x²) + (1 - x) + 3
g'(x) = -2 + 4x - 2x² + 1 - x + 3
g'(x) = -2x² + 3x + 2

g(x) naik jika g'(x) > 0
-2x² + 3x + 2 > 0
-(2x² - 3x - 2) > 0
-(2x + 1)(x - 2) > 0
x = -1/2 atau x = 2
Garis bilangan :
----- (-1/2) +++ (2) -----
Ambil daerah yg positif
-1/2 < x < 2