y=sin(x+y)求y''(隐式函数二阶导)
问题描述：
y=sin(x+y)求y''(隐式函数二阶导)
答
y'=[sin(x+y)]'(x+y)'=(1+y')cos(x+y)=cos(x+y)+y'cos(x+y)y'=cos(x+y)/[(1-cos(x+y)]y''=[cos(x+y]'(x+y)'+y''cos(x+y)+y'[cos(x+y)]'=-(1+y')sin(x+y)+y''cos(x+y)-y'(1+y')sin(x+y)y''[cos(x+y)-1]=(1+y')^2sin(x...