化简sin^4α+cos^4α+2sin^2α*cos^2α-1

化简sin^4α+cos^4α+2sin^2α*cos^2α-1 化简sin^4α+cos^2α+sin^2α*cos^2α 化简:cos^4α-sin^4α+2sin^2α化简：cos^4α-sin^4α+2sin^2α sinα-cosα×tanα-sin^4α-sin^2α×cos^2-cos^2α 求最后结果 已知sinα-2cosα=10求(sinα-4cosα)/(5sinα+2cosα) 已知sinΘ+cosΘ=2sinα,sinΘ*cosΘ=sin²β,求证：4cos²2α=cos²2β 已知sinθ+cosθ=2sinα,sinθ*cosθ=sin²β,求证：4cos²2α=cos²2β 化简sin(π/4+α)cosα-sin(π/4-α)sinα 化简sin(α-5π)/cos(3π-α)×cos(π/2-α)/sin(α-3π)×cos(8π-α)/sin(-α-4π) 化简 {sin(π+α)cos(α-2π)tan9π/4}/sin(-α)sin(7π/2+α)过程 sin^6а+cos^6а+3sin²аcos²а化简=(sin^2α+cos^2α)(sin^4α-sin^2α*cos^2α+cos^4α)+3sin^2α*cos^2α这一步的sin四次方是怎么出来的?看不懂,求这一步的详写. 化简sin^2α+sin^2β+2sinαsinβcos(α+β) 化简：2cos²α-1/【2sin(π/4-α)sin²(π/4+α)】 化简：2cos²α-1/【2sin(π/4-α)sin²(π/4+α)】 化简sin^4α+cos^4α+1/2sin²2α=? 化简4(sinα)^2+2sinαcosα-1 2sinα-3cosα/4sinα-9cosα=-1,则9sin^2α-3sinαcosα-5= 化简4sin²α-sinαcosα-3cos²α=0