Question

Tolong dong, udah mentok

Answer 1

1)
y = 2sin x + sin 2x
y ' = 0
 y ' = 2cos x + 2 cos 2x = 0
2cos x + 2(2cos² x - 1) = 0
4 cos²x + 2cos x - 2 = 0
2cos²x + cos x - 1 = 0
(2 cos x - 1)( cos x  +1) = 0
cos x = 1/2  , x = π/3  y = 2. 1/2√3 + 1/2√3 = 3/2√3) titiknya ( π/3, 3/2√3)
cos x = -1 x = π , y = 2.0+ 0 = 0 titiknya ( π , 0)

2)
y = cos²x - cos x
y'=0
y'=2cosx(-sinx) + sin x = 0
y' = sin x( 1 - 2cosx) = 0
sin x = 0, x = 0 y = 1-1 = 0 titiknya (0, 1)
1-2cos x = 0 maka cos x = 1/2 , x = π/3 , y = -1/4 titiknya (π/3, - 1/4)