已知sina=1/3,则sin(a+π/4)cos(a+π/4)

已知sina=1/3,则sin(a+π/4)cos(a+π/4) 已知sina/cosa=-2,则sin(a-3π）+cos（π-a)/sin（-a)-cos(π+a） 已知sina+sin^2a=1,求3cos^2a+cos^4a-2sina+1 sin(a-B)cosa-1/2[sin(2a+B)-sinB]=?已知cos(a-π/6)+sina=4√3/5则si 已知cos(a-π/6）+sina=4根号下3/5,则sin(a+7π/6)=? 已知cos（a-π/6）+sina=4√3/5,则sin(a+7π/6)=? 已知cos(a-π/6)+sina=(4*根号3)/5,则sin(a+7π/6)的值是( ) 已知tana=2 求sin²a-sina*cos(a-4π)+2的值 化简：sin(a-B)cosa-1/2[sin(2a+B)-sinB]=?已知cos(a-π/6)+sina=4√3/5 sin(a+π/3)+sina= - 4根号3/5,则cos(a+2π/3) 已知sina+cosa=1/3,求sin^a+cos^4a 已知cos(a-π/6)+sina=4√3/5,求sin(a+7π/6)的值为