设sinα+cosα=7/13,则sin2α=

设sinα+cosα=t,则sinαcosα 设sinα+cosα=7/13,则sin2α= 设sinα-sinβ=1/3,cosα+cosβ=1/2,则cos(α+β)=? 设α,β,γ∈(0,π/2),且sinβ+sinγ=sinα,cosα+cosγ=cosβ,则β-α= 3sinα=2cosα,则 cosα-sinα/cosα+sinα/ cos3sinα=2cosα,则cosα-sinα/cosα+sinα/cosα+sinα/cosα-sinα 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 设tanα=2,则sinα＋cosα／sinα＋cosα= 设tan(π+α)=2,则sin(α-π)+cos(π-α)/sin(π+α)-cos(π+α)= 设α为锐角,且sinα=3cosα,则sinα×cosα的值等于? 设tanα=2,计算sinα+cosα／sinα-cosα 设tanα=2,计算sinα+cosα/sinα-cosα急 设f(sinα+cosα)=sinα*cosα 则f(0)+f(1)的值~! 设sinα-cosα=1/2,求sinα*cosα= 设sinα+cosα=m,若sin^3α+cos^α 设α,β∈R,A(cosα,sinα),B(cosβ,sinβ),则|AB|max= 设向量a=(cosα,sinα),b=(cosβ,sinβ),且0 设向量a=(cosα,sinα),b=(cosβ,sinβ),且0 设向量a=(cosα,sinα),b=(cosβ,sinβ),且0