y=x+cosx⼀x+sinx的导数是多少

2024-10-29 22:54:54
推荐回答(1个)
回答1:

解:
y=(x+cosx)/(x+sinx)
y'=[(x+cosx)'(x+sinx)-(x+cosx)(x+sinx)']/(x+sinx)²首绝
=[(1-sinx)(x+sinx)-(x+cosx)(1+cosx)]/(x+sinx)²
=(x+sinx-xsinx-sin²x-x-xcosx-cosx-cos²x)/(x+sinx)²
=(sinx-xsinx-sin²x-xcosx-cosx-cos²x)/(x+sinx)²
=[(sinx-cosx)-x(sinx+cosx)-(sin²游芹链x+cos²x)]/(x+sinx)²
=(sinx-cosx-xsinx-xcosx-1)/(x+sinx)²

用到的公式:神孙
x'=1
(sinx)'=cosx
(cosx)'=-sinx
(u/v)'=(u'v-uv')/v²