sin(a-b)cosa-cos(a-b)sina=3/5 求sinb
已知cos(a-b)=3/1,求(sina+sinb)(sina+sinb)+(cosa+cosb)(cosa+cosb
已知SINA+SINB=3/5,COSA+COSB=4/5,求COS(A-B),SIN(A+B)+COS(A+B)
已知cosa-cosb=1/2,sina-sinb=-1/3,求cos(a-b),sin(a+b)
已知sina+sinB=-2/3,cosa-cosB=1/3.求cos(a+B),sin(a+B)
已知 sina+sinb=1/4 ,cosa+cosb=1/3 求sin(a+b) ,cos(a+b)的值
1.SinA+SinB=a,CosA+CosB=1+a,求Sin(A+B),Cos(A+B).
已知cosa+cosb=3/5,sina+sinb=4/5,求cos(a+b)
(1)已知:sina+cosb=3/4,cosa+sinb=-5/4,求sin(a+b).
已知sina+cosb=3/4,cosa+sinb=-5/4,求sin(a+b)
证明下列恒等式:sin(a+b)*cos(a-b)=sina*cosa+sinb*cosb
化简:sin(a-B)cosa-1/2[sin(2a+B)-sinB]=?已知cos(a-π/6)+sina=4√3/5
sin(a-B)cosa-1/2[sin(2a+B)-sinB]=?已知cos(a-π/6)+sina=4√3/5则si