ysinx-cos(x+y)=0,求 dy/dx

来源:百度知道 编辑:UC知道 时间:2024/06/24 10:08:49
ysinx-cos(x+y)=0,求 dy/dx

解:应用复合函数求导方法,
y′sinx+ycosx+(1+y′)sin(x+y)=0,
(sinx+sin(x+y))y′+ycosx+sin(x+y)=0,
y′=-(ycosx+sin(x+y))/(sinx+sin(x+y)).
故 dy/dx=y′=-(ycosx+sin(x+y))/(sinx+sin(x+y)).

两边同时求导
y'sinx+ycosx+(1+y')*sin(x+y)=0
整理
y'=-[y*cosx+sin(x+y)]/[sinx+sin(x+y)]