两边同时取对数,有ln z = ylnx+xlny上式两边对X求导,有1/z dz/dx=y/x + lny所以dz/dx=(y/x + lny)(x^y+y^x)
z=x^y+y^xdz/dx = y*x^(y-1) + (y^x) *lny
dz/dx =y*x^(y-1)+lny*y^x
z=x^y+y^xdz/dx = y*x^(y-1) + (y^x) *lny dz/dx =y*x^(y-1)+lny*y^x
先把d约去