解微分方程：y` cos y =(1+cos x sin y)sin y.

Matlab编程问题 cos(x*y)*cos(x*(1-y))-0.5x*sin(x*y)*sin(x*(1-y))= Sin x-sin y=2/3 cos x-cos y=1/2 求cos(x-y) sin(x+y)sin(x-y)=k,求cos^2x-cos^2y 证明COS（X+Y）COS（X-Y）=COS^2X-SIN^2Y 求证 cos*xcos*y + sin*xsin*y + sin*xcos*y + xin*ycos*x = 1 化简sin(x+y)cos(x-y)+cos(x+y)sin(x-y) x*y'*sin(y/x)-y*sin(y/x)+x=0 求微分方程的解 cos（x+y）=?sin（x+y）=? y =(cos^2) x - sin (3^x),求y' 求证sin^2x+sin^2y-sin^2x*sin^2y+cos^2x*cos^2y=1 y=cos x/(1-sin x)的导数 求导y=(1+sin^2 x)/(cos(x^2))