cos x sin x=3,求cos x+sin x
已知tan=2,求(cos x+sin x)/(cos x-sin x)+sin^2x
cos x sin x=3,求cos x+sin x
sin(sin(sin(sin(x)=cos(cos(cos(cos(x),X等于多少?
求导f(x) = cos(3x) * cos(2x) + sin(3x) * sin(2x).
Sin x-sin y=2/3 cos x-cos y=1/2 求cos(x-y)
y =(cos^2) x - sin (3^x),求y'
证明sin^2(x)+cos^2(x+30)+sin(x)cos(x+30)=3/4
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
已知cos 2x=3/5,求sin^4 x+cos^4 x的值
化简sin(x)(cos(x)+cos(3x)+cos(5x)+cos(7x))
sin(-x)=sin(x),cos(-x)=-cosx对吗?