化简(sin(x+y)-2cosxsiny)除2sinxsiny+cos(x+y)
证明COS(X+Y)COS(X-Y)=COS^2X-SIN^2Y
化简sin(2x-y)*sin y+cos(2x-y)*sin y
若cosxcosy+sinxsiny=12,sin2x+sin2y=23,则sin(x+y)= ___ .
化简y=sin^2(x)+2sin(x)cos(x)+3cos^2(x)
求证:sin(x-y)/(sinx-siny)=cos[(x-y)/2]/cos[(x+y)/2]
sin(x+y)sin(x-y)=k,求cos^2x-cos^2y
y=sin^2x+sinxcoswx+cos^2x 化简
化简y=(cos x)^2+sin x -2 谢谢
y=cos(-x)求导 1)y=cos(-x)=cos x y'=-sin x 2)y'=-sin(-x)= sin x
sin(x+y)-sinx=2cos(x+1/2y)sin(1/2y)的详细证明步骤.
函数y=cos(x+π/2)+sin(π/3-x)化简
cos(x+y)sinx-sin(x+y)cosx