若sin(π/2+α)=cos(π-α),则a的取值集合为

若cosα>sinα,(-π/2 若sin(α-π)=2cos(2π-α),求（sinα+5cosα）/（sinα-3cosα）的值, 若（sinα+cosα）/（sinα-cosα）=2 则sin(α-5π)·sin(3π/2-α)=? 若sinα+cosα/sinα-cosα=2,则sin(α-5π）*sin（3π/2-α）等于? 若(sinα+cosα)/(sinα-cosα)=2,求sin(α-5π)sin(3π/2-α)的值 若cosα/sin(α-π/4)=-根号2/2,则cosα+sinα的值为、 cos^2(π/4+α)=(cos(π/4)cosα-sin(π/4)sinα)² cos^2(π/4+α)是怎么等于(cos(π/4)cosα-sin(π/4)sinα)²的? sin(α-π)=2cos（α-2π）求cos平方α-sin平方αcosα 若sinα=1/2,则sin(π/4-α)cos(π/4-α)= sin(π-α)=-2sin(π/2+α),则sinαcosα等于 sin(π-α)=-2sin(π/2+α),求sinα·cosα 已知sin(3π-α)=-2sin(π/2+α)则sinαcosα 设角a=-35π/6,则2sin(π+α)cos(π-α)-cos(π+α)/ 1+sin^2α+sin(π-α)-cos^2(π+α)sina=sin(-35π/6)=sin(-6π+π/6)=1/2 cosα=根号3/22sin(π＋α)cos(π-α)-cos(π+α)/ [1+sin^2α+sin(π-α)-cos^2(π+α)]=2（-sinα)(-cosα）+cosα/[1+sin² 若(4sinα-2cosα)/(5cosα+3sinα)=10,且α∈(-π/2,0)则cosα值为 若sinαsinβ+cosαcosβ=0,则sinαcosα+sinβcosβ= .1若sinαsinβ+cosαcosβ=0,则sinαcosα+sinβcosβ= 2已知sin(α+β)=1,则cos(α+2β)+sin(2α+β)=急, 已知0＜α＜π/2,且3sinα=4cosα求(sin^2α+2sinαcosα)/(3cos^2α-1)求cos^2α+sinαcosα 已知sinα+cosα=4/5且3π/22,若sinα+sinβ+sinγ=0,cosα+cosβ+cosγ=0,则cos(α-β)的值 已知6sin²α+sinαcosα-2cos²α=0,α∈（π/2,π）,求值1).(sinα-3cosα）/（sinα-cosα）；2）.sinαcosα-sin²α;3).sin²α-3cosαsinα-2