sin x－cos x=1/3 则,sin2x=（）.

若cos x-sin x = 0.5,则cos^3 x-sin^3 x = 若sin x/2 - cos x/2 = 1/3,则sin x=? 若sin x/2-cos x/2=1/3,则sin x= 已知(1+sin x)/cos x=-1/2,则cos/(sin x-1)=? 若cos(x+y)cos(x-y)=1/3,则cos^x-sin^y=?^为平方 1/cos(x) - tan(x) = 3 求sin(x)1/cos(x) - tan(x) = 3求sin(x) 傅里叶级数作图f（x）=2sin[x] - sin[2x] + 2/3sin[3x] - 1/2sin[4x]我用mathematica输入程序Plot[{2sin[x],-2sin[x],2sin[x] - sin[2x],-2sin[x] + sin[2x],2sin[x] - sin[2x] + 2/3sin[3x],-2sin[x] + sin[2x] - 2/3sin[3x],2sin[x] - sin[2x] + 2/3si 已知sin(x)+3cos(x)=2,求sin(x)-cos(x)/sin(x)+cos(x)=? sin x－cos x=1/3 则,sin2x=（）. sin x－cos x=1/3 则,sin2x=（）. 要过程,有好评! (1+cos x-sin x)/(1-sin x-cos x)+(1-cos x-sin x)/(1-sin x+cos x)=? 求证(3-sin^4 x-cos^4 x)/2cos^2 x=1+tan^2 x+sin^2 x Sin x-sin y=2/3 cos x-cos y=1/2 求cos(x-y) cos x/sin x+sin x/(1+cos x) 化简. 2sin^2x - 5sin x cos x=3 cos^2x,求X, 解方程：cos^3x-sin^3x=1 求方程 sin^3x+cos^5x=1 若SIN X*COS X =1/3,已知0