cos2x的导数为什么不是sin2x

2024-12-19 14:55:30
推荐回答(1个)
回答1:

y = cos (2x) 令:u=2x y=cosu dy/dx = (dy/du)(du/dx) = -sinu * 2 = -2sin (2x) 复合函数求导!
y'= -2sin(2x)