F(x)=cos (4x^2+2x-1) Ditanya F'(x)

jawab

y = cos (4x² + 2x  -1)
u = 4x² + 2x - 1
du/.dx = 8x + 2

y = cos u
dy./du = - sin u

y' = dy/du. du/dx
y' = - sin u . (8x+2)
y' = - (8x +2) sin (4x² + 2x -1)