化简cos2(-α)-tan(2π+α)/sin(-α)

sin2(-α)+tan(2π+α)cos2(π+α）-sin（2π-α）cos(π+α）cos2(π+α）化简 求助各 sinα=cos2α,α∈[π/2,π],求tanα tan(α+π/4)=2,则cos2α+3sin^2α+tan2α=? 已知tan[α+π/4]=2,求cos2α+3sin²α的值 (1)已知tan(π/4+α)=2,求tanα,sin2α+sin^2α+cos2α tan^2α=2tan^2 β+1则 cos2α+sin^2β等于? 已知sin²2α+sin2αcos2α-cos2α=1,α∈（0,π）求sinα,tanα 已知sinα=2sinβ，tanα=3tanβ，求cos2α的值． 2sin2α-cos2α+sinαcosα-6sinα+3cosα=0,求2cos2α+sinαcosα/1+tanα. 已知tan(π/4+α)=2 求(cos2α-sin2α)/(2sinαcosα+cos^2α) α为锐角,且tan(π/4+α)=2,求(sin2αcosα-sinα)/cos2α 已知tan(π/4+α)=2,求1/(2sinαcosα+cos2α)的值.