化简sin(π/4+A)cosA-cos(π/4+A)sinA=
Sin^4a+Sina*Cosa+Cos^2a化简
若cos(a+B)*cosa+sin(a+B)*sina=-4/5,则sin(π/2-B)
sin(π+a)=sinπcosa+cosπsina=-sina中sinπcosa+cosπsina=-sina是怎么得
化简:sin(a-B)cosa-1/2[sin(2a+B)-sinB]=?已知cos(a-π/6)+sina=4√3/5
化简sina^8-cosa^8-sin^6a+cos^6a+sin^4a
cos(π-2a)/sin(a-π/4)=-√2/3 求cosa+sina=_ 求推导
1.化简3(sina+cosa)^4+6(sina-cosa)^2+4(sin^6a+cos^6a)
已知sina/cosa=-2,则sin(a-3π)+cos(π-a)/sin(-a)-cos(π+a)
已知[sina(a-π/4)]/cos(π+2a)=根号2,则sina+cosa=?
cosa-cosβ=4/5 sina-sinβ=3/5 求cos(a-β)
1:已知sina+cosa=根2求sina cosa sin(4方)a+cos(4方)的值
对于任意a属于(0,π/2) 比较sin(sina) sin(cosa) cos(a) cos(sina) cos(co