化简sin(25π/12)cos(11π/6)-cos(11π/12)sin(5π/6)的值是
化简sin(25π/12)cos(11π/6)-cos(11π/12)sin(5π/6)的值是
求证sin^2α+cosαcos(π/3+α)-sin^(π/6-α)的值与α无关
sin^2(α)+cosαcos(π/3+α)-sin^2(π/6-α)为定值,要证明
【1】化简:sin(a-5π)/cos(3π-a)×cos(π/2-a)/sin(a-3π)×cos(8π-a)/sin
已知tan(π-α)=2,求sinα-2sinαcosα-cosα/4cosα-3sinα的值
已知α=7/12π,那么cosα√(1-sinα)/(1+sinα)+sinα√(1-cosα)/(1-cosα)=
已知sinβ+cosβ=1/5,β∈(0,π) (1)求sinβ.cosβ,sinβ-cosβ的值 *(2)求sin,c
(cosπ12-sinπ12)(cosπ12+sinπ12)= ___ .
化简:cos(a-π/2)/sin(5π/2+a)*sin(a-2π)*cos(2π-a)
化简:[ cos(α-π/2)/sin(5π/2+α) ] ×sin(α-2π) × cos(2π-α)
已知tan(α+π/4)=3,求cosα+2sinα/cosα-sinα的值
已知sinα+cosα=2/3,α属于(0,π),求sinα-cosα的值