帮帮忙拜托啦u=ln(x^y乘y^z乘z^y)求du

帮帮忙拜托啦u=ln(x^y乘y^z乘z^y)求du
帮帮忙拜托啦u=ln(x^y乘y^z乘z^y)求du

帮帮忙拜托啦u=ln(x^y乘y^z乘z^y)求du
u = ln(x^y)+ln(y^z)+ln(z^x) = ylnx+zlny+xlnz
所以
∂u/∂x = y/x + lnz
∂u/∂y= lnx+ z/y
∂u/∂z= lny + x/z
所以du = (y/x + lnz)dx + (lnx+ z/y)dy + (lny + x/z)dz