sina=1/3,a∈(0,π/4),则sin(2a-π/6)
sina=1/3,a∈(0,π/4),则sin(2a-π/6)
已知sina/cosa=-2,则sin(a-3π)+cos(π-a)/sin(-a)-cos(π+a)
已知sin(2π-a)=4/5,a∈(3/2π,2π),则(sina+cosa)/(sina-cosa)等于
1- sin(2π/3 - a)/sina
sinA+cosA=1/2,则sin(A+π/4)=?
若sina+cosa=1/2,则sin(a+π/4)=?
已知sinA+cosA=1/5,A∈(0,π),求sinA,cosA及sin^3A+cos^3A
若(sina+cosa)/(sina -cosa)=2,则 sin(a-5π)*(乘) sin(3π/2 - a)等于?
已知sin(π+a)=1/3,则sina=
sin(a-B)cosa-1/2[sin(2a+B)-sinB]=?已知cos(a-π/6)+sina=4√3/5则si
若sinA+cosA/sinA-cosA=2,则sin(A-5π)*sin(3π/2-A)等于?
已知cos(a-π/6)+sina=4根号下3/5,则sin(a+7π/6)=?