sin (973/2π) ,sin (374/2) sin(374/6)求三角函数值,

计算,sin(π/12)-sin(5π/12)+2sin(π/8)sin(3π/8) 化简sin(α+β)+sin(α-β)+2sinαsin(3π/2-β)= sin^2(π/3-x)+sin^2(π/6+x) 2sin(α+π/3）=sinα+______ Sin(π+π/6)Sin(2π+π/6)Sin(3π+π/6).Sin(2008π+π/6)求值 sin (973/2π) ,sin (374/2) sin(374/6)求三角函数值, 2sin π/6 =sin π/3,吗,求解释,还有-sin π/6=sin- π/6吗 化简求sin^2(a-π/3)+sin^2(a+π/3)+sin^2a 求sin^2α+sin^2(π/3 +α)+sin^2(π/3 -α) 化简；sin^2 A+sin^2(A-π/3)+sin^2(A+π/3) 化简 sin²x+sin²(x+2π/3)+sin²(x-2π/3) 化简sin^2A+sin^(A-π/3)+sin(A+π/3) 已知sin(3π-α)=-2sin(π/2+α)则sinαcosα sin(-π/3) sinπ/2是什么意思 sin a+sin 2a +sin 3a +...+sin na怎么求和? sin a+sin 2a +sin 3a +...+sin na怎么求和? sin²1°+sin²2°+sin²3°+.+sin²89