cos(π/4+α)+sin(π/4+α) ,,

利用和差角公式化简 (2)sin(π/3+α)+sin(π/3-α)(2)sin(π/3+α)+sin(π/3-α)(3)cos(π/4+α)-cos(π/4-α)(4)cos(60°+α)+cos(60°-α)(5)sin(α-β)cosβ+cos(α-β)sinβ(6)cos(α+β)cosβ+sin(α+β)sinβ 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? 化简sin(π/4+α)cosα-sin(π/4-α)sinα 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 化简sin(α-5π)/cos(3π-α)×cos(π/2-α)/sin(α-3π)×cos(8π-α)/sin(-α-4π) 已知sin(3π+α)=2cos(α-4π)求cos(π/2 -α)+5sin(π/2 +α)/2cos(π+α)-sin(-α) 已知tan（π-α）=2,求sin²α-2sinαcosα-cos²α/4cos²α-3sin²α+1 已知tan（π-α）=2,求sinα-2sinαcosα-cosα／4cosα-3sinα的值 化简sin(α-2π)+sin(-a-3π)cos(α-3π)/cos(π-α)-cos(-π-α)cos(α-4π) 已知sin a=2cos a 计算⑴（sinα+2cosα)/(5cosα-sinα) ⑵tan(α+π/4) 化简sin(π/4-α)+cos(π/4+α) cos(π/4+α)+sin(π/4+α) ,, 关于三角函数诱导公式的证明题求证：[Sin(α-3π)+cos(α-4π)]/{[Cos(α-π)/sin(α-π)]-tan(α-π)}=[sin(4π-α)cos(2π-α)]/[cos(π-α)+sin(π+α)] ①[4sin（α-π）-sin（3π/2-α）]/[3cos(α-π/2）-5cos（α-5π）] ②sin^2-2sin^2αcosα-cos^2α 化简【cos(π/4+α)-sin(π/4+α)】/【cos(π/4-α)+sin(π/4-α)】.如题 化简:sin(π/4-α)cos(π/3-α)-cos(π/6+α)sin(π/4+α)= sin(π/4+α)怎么化为cos的形式?