cos^2 x - sin^2 x 是怎么化简=cos 2x
cos^2 x - sin^2 x 是怎么化简=cos 2x
(sin^2x+cos^2x )(sin^2x-cos^2x)怎么得sin^2x-cos^2x?
已知tan=2,求(cos x+sin x)/(cos x-sin x)+sin^2x
求导f(x) = cos(3x) * cos(2x) + sin(3x) * sin(2x).
lim(sin(x^2*cos(1/x)))/x怎么做?
cos 2x /sin^2 x*cos^2 x不定积分
2cos x (sin x -cos x)+1
化简y=sin^2(x)+2sin(x)cos(x)+3cos^2(x)
证明sin^2(x)+cos^2(x+30)+sin(x)cos(x+30)=3/4
证明COS(X+Y)COS(X-Y)=COS^2X-SIN^2Y
已知(1+sin x)/cos x=1/2,则cos x/(sin x-1)的值是
1.化简根号2cos x - 根号6sin x2.已知sin(α-β)cosα-cos(β-α)sinα=3/5,β是第