已知sin(a+π/6)=3/5 ,60°
已知sin(π/6+a)=1/3,求sin(5/6π-a)+cos2(7/6π+a)
已知sin(a+π/6)+cosa=4/5倍根号3,则sin(a+π/3)=
已知sin(π/6+a)=(根号3)/3,求sin(2π/3+a)?
已知sin(30+a)=3/5,60
已知(4sin a-2cos a)/(5cos a +3sin a)=6/11,求cos^4 a-sin^4 a
已知3SIN^2A+2SIN^2B=5SINA,求SIN^2A+SIN^2B范围
已知sin(a+π/6)=4/5 a∈(0,π/3) 求cosa
已知cos(π/2+a)=2sin(a-π/2)求sin(π-a)+cos(a+π)/5cos(5π/2-a)+3sin
已知sin(a-3π)=2cos(a-4π),求(sin(π-a)+5cos((3π/2)-a))/(2sin(3π/2
已知方程sin(a-3π)=2cos(a-4π),求 [sin(π-a)+5cos(2π-a)]/[2sin(3π/2-
已知sin(π+a)=-1/2,计算:sin(5π-a)和cos(a-(3π/2))
已知sin[a-b]cos a-cos[b-a]sin a=3/5,b是第三象限角,求sin[b+5π/4]的值