sin(−π3)+2sin4π3+3sin2π3

化简sin^3α×sin3α+cos^3α×cos3α+1/2sin2α×sin4α 化简:(sinα-cosα)^2+sin4α/2cos2α 化简:sin^2x+sin^2(x+2π/3)+sin^2( sin2/3π=sin(π-π/3)吗? 若sin(π/4+α)=sinθ+cosθ,2sin^2β=sin2θ,求证：sin2θ+2cos2β=3 sin(α+π/4)=1/3,则sin2α sin2（π3 证明：sinπ／9[（sinπ／9)+sin(3π／9)]=sin2(2π／9） 已知α∈(π/2,π),且sinα=3/5,则sin^2α/2+(sin4αcos2α)/(1+cos4α)的值为多 若cos4分之πcosθ-sin4分之3πsinθ=0,θ的绝对值 Θ∈(π/2,3π/4) sin2Θ∈a sinΘ+cosΘ 已知sin2α=2sin4°,求证tan(α+2°)=3tan(α-2)° 已知函数f(x)＝23sin(x−3π)sin(x−π2)+2sin2(x+5π2)−1，x∈R