2sin^2X*cos^2X为什么会=1-1/2sin^2*2X
为什么y = x - sin(x/2)cos(x/2) = x - (1/2)sin(x) 其中sin(x/2)cos(
已知tan=2,求(cos x+sin x)/(cos x-sin x)+sin^2x
求证(cos^2 x-sin^2 x)(cos^4 x+sin^4 x)+1/4 sin 2x sin 4x=cos 2
2cos x (sin x -cos x)+1
化简[1-(sin^4x-sin^2cos^2x+cos^4x)/(sin^2)]+3sin^2x
证明(1-2sin x cos x )/(cos^2x-sin^2x)=(1-tan x)/(1+tan x)
(1-(sin^4x-sin^2xcos^2x+cos^4x)/sin^2x +3sin^2x
5sin^2(X)+sin(2X)-cos^2(X)=1, 求解X
化简 1/2cos x-根号3/2sin x 根3sin x+cos x
三角等式求证:cos^6x+sin^6x=1-3sin^2x+3sin^4x
求导f(x) = cos(3x) * cos(2x) + sin(3x) * sin(2x).
sin(兀/2+△x)-sin兀/2 =cos△x-1为什么