x/y+√（y/x）=1 两边对x求导：(y-xy')/y^2+1/[2√(y/x)]*(y'x-y)/x^2=02x^2(y-xy')+y^2(xy'-y)/√(y/x)=0这样只能得y-xy'=0,得:y'=y/x(这题从方程即可求得y=kx,其中k为常数）sin（xy）-ln[（y+1）/y]=1两边对x求导...