化简 1+sin(x-360°)*cos(x-270°)-2*cosx*cosx
化简cos(X-30°)+sin(X+30°)+cosX+1
化简F(X)=2(COSX)^2+2 sin x cos x+1
化简:{(1+sinx+cosx)[sin(x/2)-cos(x/2)}/根号下的(2+2cosx)
化简sin^4x/sinx-cosx - (sinx+cosx)cos^2x/tan^2x-1
1、cos(x+B)*cos(x-B)=cosx-sin^2B
为什么cosX+cos²X-sinX-sin²X=(cosX-sinX)(1+sinX+cosX)
化简:1.【(sin^2)(-X-π) *cos(π+X)cosX】/【tan(2π+X) *(cos^3 (-X-π)
(1)已知sinx+cosx=根号2/2,求sin^4x+cos^4x
cos(x+y)sinx-sin(x+y)cosx
sin(x+1/2π)=cosx?还是cos-x
已知向量a=(1-cosx,2sin x/2),向量b=(1+cosx,2cos
化简2sinx*cosx*cos(2π-x)+cos(π+2x)*cosx*tanx