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