求微分方程y′cosy=(1+cosxsiny)siny
求微分方程cosy*dy/dx+siny=(x+1)的通解
求下列微分方程的通解(cosy)dy/dx-siny=0
已知cosx+cosy=1/2,sinx-siny=1/3,求cos(x+y)
sinx+siny=1/4,cosx+cosy=1/3求tan(x-y)
sinx+siny=-1/3 cosx+cosy=1/2,求sin(x+y)的值.
cosx-cosy=4/1,sinx-siny=3/1求cos(x-y)
sinx+siny=1求cosx+cosy的范围
已知sinx+siny=1/3,求sinx-cosy*cosy的最大值和最小值.
已知sinx+siny=1/3,cosx-cosy=1/5,求cos(x+y),sin(x-y).
已知sinx-siny=1/2,cosx-cosy=1/2,x、y均为锐角,求sin(x-y)
设cosX+cosY=1/2,sinX+sinY =1/4,求cos(X-Y)的值
设sinX+sinY=1/4,cosX+cosY=1/3,求tan(X+Y)的值.要详解.