化简①sin(π+α)×cos(3π/α)+sin(π/2+α)×cos(π+α)
已知(3sinα+cosα)/(3cosα-sinα)=2,则2-3sin(α-3π)sin(1.5π-α)-[cos(
α∈(0,π/2 ),比较 sin(cosα) 与cos(sinα)大小
化简[sin(π/2-α)cos(π/2-α)]/cos(π+α)-[sin(π-α)cos(π/2-α)]/sin(π
已知tan(3π+α)=2,求:1、(sinα+cosα)²;2、sinα-cosα/2sinα+cosα
已知tan(π-α)=2,求sinα-2sinαcosα-cosα/4cosα-3sinα的值
若sinα+cosαsinα−cosα=2,则sin(α-5π)•sin(3π2-α)等于( )
若(sinα+cosα)/(sinα-cosα)=2 则sin(α-5π)·sin(3π/2-α)=?
α属于(0,π/2)且2sin²α-sinαcosα-3cos²α=0求sin(α+π/4)/sin
化简:[ cos(α-π/2)/sin(5π/2+α) ] ×sin(α-2π) × cos(2π-α)
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
已知tan(α+π/4)=3,求cosα+2sinα/cosα-sinα的值