e^xy+x+y=2求dy/dx |x=1
问题描述:
e^xy+x+y=2求dy/dx |x=1
答
f(x,y)=e^xy+x+y=2求全微分 (Df/Dx)dx+(Df/Dy)dy=0dy/dx=-(y*e^xy+1)/(x*e^xy+1)如果 x=1dy/dx |x=1 = -(ye^y+1)/(e^y+1)其中y为 f(1,y)=2 的解,即y满足 e^y+1+y=2=>e^y+y=1 => y=0 (这是特殊情况,一般此类方程没有...