cos(π/6+a)=根号3/3 求sin(5π/6-a)=?
求证 cos(A)+ 根号3sin(A)=2sin(π/6+A)
已知cos(π/6-a)=根号3/3,求cos(5π/6+a)-sin²(a-π/6)的值.
已知cos(π/6-a)=根号3/3,求cos(5π/6+a)-sin²(a-π/6)的值.
已知cos( π /6-a)=根号3/3,求cos(5π /6+a)-sin^2(a-π /6)的值
已知cos(π/6-a)=(根号3)/2,求cos(5π/6+a)-sin平方(a-π/6)的值
(1)已知cos[(π/3)-a]=根号3/3,求sin[5π/6)-a]+sin^2[(2π/3)+a]的值
已知cos(π/6-a)=根号3/3,求cos(5π/6+a)-cos²(π/3+a)
已知sin(π/6-a)=根号3/3,则 cos(4π/3+a)
已知(4sin a-2cos a)/(5cos a +3sin a)=6/11,求cos^4 a-sin^4 a
已知cos(π/2+a)=2sin(a-π/2)求sin(π-a)+cos(a+π)/5cos(5π/2-a)+3sin
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*根号3)/5,则sin(a+7π/6)的值是( )