z=sinx/sin(x+y)偏导怎么求?如题,sinx/sin(x+y)偏导

Answer 1

az/ax=(cosxsin(x+y)-sinxcos(x+y))/sin^2(x+y)
=sin(x+y-x)/sin^2(x+y)
=siny/sin^2(x+y)
az/ay=sinx*(-1/sin^2(x+y))*cos(x+y)
=-sinxcos(x+y)/sin^2(x+y)