若sin((π/6)-α)=1/3,则cos((2π/3)+2α)等于多少?
若sinα+cosαsinα−cosα=2,则sin(α-5π)•sin(3π2-α)等于( )
已知sin(2π-α)=45,α∈(3π2,2π),则sinα+cosαsinα-cosα等于( )
若(sinθ+cosθ)/(sinθ-cosθ)=2,则sin(θ-5π)*sin(3π/2-θ)等于?
已知sin(π/4+α)=2/3,则cos(π/4-α)的值等于多少?
若tanα=1/3则sin^2α+sinαcosα+2cos^2α等于多少
已知(3sinα+cosα)/(3cosα-sinα)=2,则2-3sin(α-3π)sin(1.5π-α)-[cos(
sin(3π+α)=-1/2,则cos(7π/2-α)=多少?
若(sinα+cosα)/(sinα-cosα)=2 则sin(α-5π)·sin(3π/2-α)=?
sin(sin(sin(sin(x)=cos(cos(cos(cos(x),X等于多少?
若cos(α+β)cos(α-β)=1/3 则cos²α-sin²β等于
2sin²α-sinαcosα-3cos²α=0,α∈(0,π/2),那么sinα=多少?
若α,β∈(0,2/π).cos(α-β/2)=√3/2,sin(α/2-β)=-1/2.则cos(α+β)等于多少?