Question

y=tan(x+y)的导数怎么求,我求出来的都有三角函数符号,-（1+1/y^2）

Answer 1

y*cos(x+y)=sin(x+y)

两边对x求导

y'cos(x+y)-ysin(x+y)(1+y')=cos(x+y)(1+y')

-ysin(x+y)(1+y')=cos(x+y)

-ytan(x+y)(1+y')=1

-y^2(1+y')=1

y'=答案