为什么4*sin(2x+∏/3)*cos(2x+∏/3)=2sin(4x+2∏/3)
证明sin^2(x)+cos^2(x+30)+sin(x)cos(x+30)=3/4
化简[1-(sin^4x-sin^2cos^2x+cos^4x)/(sin^2)]+3sin^2x
(1-(sin^4x-sin^2xcos^2x+cos^4x)/sin^2x +3sin^2x
求导f(x) = cos(3x) * cos(2x) + sin(3x) * sin(2x).
化简下面的三角函数f(x)=sin^2x+2√3sin(x+∏/4)cos(x-∏/4)-cos^2-√3
三角等式求证:cos^6x+sin^6x=1-3sin^2x+3sin^4x
sin(5x)-sin(3x)= 根号2cos(4x)
化简y=sin^2(x)+2sin(x)cos(x)+3cos^2(x)
根据下列条件求函数f(x)=sin(x+∏/4)+2sin(x-∏/4)-4cos2x+3cos(x+3∏/4)的值 (
已知sin X+cos X=m,|m|小于等于根号2且|m|不等于1,求sin X^3+cos X^3,sin X^4+
化简2sin^2[(π/4)+x]+根号3(sin^x-cos^x)-1
已知cos 2x=3/5,求sin^4 x+cos^4 x的值