Posted by haifeng on 2021-11-15 09:09:33 last update 2021-11-15 09:10:15 | Answers (1) | 收藏
1. $y=e^x(x\cos x-\sin x)$
2. $y=\dfrac{x\sin x}{1+\tan x}$
3. $s(t)=a\sin^2(\omega t+\varphi)$
