化简sin (x+y)sin x +cos (x+y)cos x=
化简sin(x+y)cos(x-y)+cos(x+y)sin(x-y)
化简y=sin^2(x)+2sin(x)cos(x)+3cos^2(x)
sin(x+y)sin(x-y)=k,求cos^2x-cos^2y
证明COS(X+Y)COS(X-Y)=COS^2X-SIN^2Y
y=sin^2x+sinxcoswx+cos^2x 化简
化简y=(cos x)^2+sin x -2 谢谢
Matlab编程问题 cos(x*y)*cos(x*(1-y))-0.5x*sin(x*y)*sin(x*(1-y))=
化简sin(2x-y)*sin y+cos(2x-y)*sin y
化简sin(x+y)sinx+cos(x+y)cosx等于?
化简sin(x+y)sinx+cos(x+y)cosx
化简cos(x+y)sinx-sin(x+y)cosx
cos(x+y)=?sin(x+y)=?