化简sin(2x-y)*sin y+cos(2x-y)*sin y
化简sin(2x-y)*sin y+cos(2x-y)*sin y
sin(x+y)sin(x-y)=k,求cos^2x-cos^2y
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)
y =(cos^2) x - sin (3^x),求y'
y=sin^2x+sinxcoswx+cos^2x 化简
化简y=(cos x)^2+sin x -2 谢谢
证明COS(X+Y)COS(X-Y)=COS^2X-SIN^2Y
Sin x-sin y=2/3 cos x-cos y=1/2 求cos(x-y)
tan(x+y)tan(x-y)=sin^2x-sin^2y/cos^2x-sin^2y 顺便问一下. tan,sin,
求证sin^2x+sin^2y-sin^2x*sin^2y+cos^2x*cos^2y=1
设sin(x+y)sin(x-y)=m,则cos^2x-cos^2y的值