若sina=根号3/2,且a属于(π,3π/2),则sin(a+π/2)=-------
sin(a+π/3)+sina= - 4根号3/5,则cos(a+2π/3)
a属于(π/2,π),1/sina+1/cosa=2根号2,则sin(2a+π/3)=______
已知a属于( π/2,π)且sina=3/5.求cos(a- π/4)的值;求sin(a/2)的平方+tan(a+ π/
已知sin(3π-a)= 根号2sin(π-β),根号3cos(-a)= -根号2cos(π+β),且α β属于(0,π
若sinA+cosA/sinA-cosA=2,则sin(A-5π)*sin(3π/2-A)等于?
已知sina=3/5,且a属于(π/2,π),那么sin^2a/cos^2a的值等于?
已知sina+cosa=1-根号3/2,a属于(0,π),则cos2a=
已知sin(a+π/3)+sina=-(4倍根号下3)/5,-π/2
已知sin(a+π/3)+sina=-4根号3/5 -π/2
已知sin(a+π/3)+sina=-4根号3/5,-π/2
若sin(a-π/4)/cos2a=-根号2,则sina+cosa=
已知a属于(0,π/2),且2(sina)^2-sinacosa-3(cosa)^2=0,求sin(a+π/4)/(si