1+cos^2 2x为什么会等于(sin^2 x+cos^2 x)^2 +(sin^2 x-cos^2 x)^2
2cos x (sin x -cos x)+1
[sin^2(x)-cos^2(x)] 为什么等于-cos2x
cos 2x /sin^2 x*cos^2 x不定积分
已知tan=2,求(cos x+sin x)/(cos x-sin x)+sin^2x
(sin^2x+cos^2x )(sin^2x-cos^2x)怎么得sin^2x-cos^2x?
∫sin(x) cos^2(x)dx
化简 1/2cos x-根号3/2sin x 根3sin x+cos x
化简 cos^2(x)*sin^2(x)-sin^2(x)
化简 cos^(2)(x)*sin^(2)(x)-sin^(2)(x)
求导f(x) = cos(3x) * cos(2x) + sin(3x) * sin(2x).
化简[1-(sin^4x-sin^2cos^2x+cos^4x)/(sin^2)]+3sin^2x
求证(cos^2 x-sin^2 x)(cos^4 x+sin^4 x)+1/4 sin 2x sin 4x=cos 2