已知y=y(x)由方程cos(x+y)+e^(x-y)=2 y' y'|(x,y)=(0,0)
问题描述:
已知y=y(x)由方程cos(x+y)+e^(x-y)=2 y' y'|(x,y)=(0,0)
已知y=y(x)由方程cos(x+y)+e^(x-y)=2所确定,求y' ,y'|(x,y)=(0,0)
答
对方程两边同时求导得,﹣﹙y+xy′﹚sin﹙xy﹚+e^y+﹙x+1﹚y′e^y=0令x=0则方程cos(xy)+(x+1)*e^y=2为1+e^y=2,得y=0,即切点坐标为﹙0,0﹚将﹙0,0﹚带入﹣﹙y+xy′﹚sin﹙xy﹚+e^y+﹙x+1﹚y′e^y=0得y′=﹣...