作业帮三角比：[cos(4a-PAI/2)*sin(PAI/2-2a)]/[(1+cos2a)*(1+cos4a)]
来源：学生作业帮助网 编辑：作业帮 时间：2024/05/12 13:27:33
![三角比：[cos(4a-PAI/2)*sin(PAI/2-2a)]/[(1+cos2a)*(1+cos4a)]](/uploads/image/z/241186-58-6.jpg?t=%E4%B8%89%E8%A7%92%E6%AF%94%EF%BC%9A%5Bcos%284a-PAI%2F2%29%2Asin%28PAI%2F2-2a%29%5D%2F%5B%281%2Bcos2a%29%2A%281%2Bcos4a%29%5D)
三角比：[cos(4a-PAI/2)*sin(PAI/2-2a)]/[(1+cos2a)*(1+cos4a)]
三角比：[cos(4a-PAI/2)*sin(PAI/2-2a)]/[(1+cos2a)*(1+cos4a)]
三角比：[cos(4a-PAI/2)*sin(PAI/2-2a)]/[(1+cos2a)*(1+cos4a)]
[cos(4a-π/2)*sin(π/2-2a)]/[(1+cos2a)*(1+cos4a)]
=[cos(π/2-4a)*sin(π/2-2a)]/[(1+cos2a)*(1+cos4a)]
=(sin4a*cos2a)/[(1+cos2a)*(1+cos4a)]
=(sin4a*cos2a)/{(1+cos2a)*[1+2(cos2a)^2-1]}
=(sin4a*cos2a)/{(1+cos2a)*2(cos2a)^2}
=sin4a/{(1+cos2a)*2cos2a}
=2sin2a*cos2a/{(1+cos2a)*2cos2a}
=sin2a/(1+cos2a)
=tana
三角比：[cos(4a-PAI/2)*sin(PAI/2-2a)]/[(1+cos2a)*(1+cos4a)]
cos (a+4pai)cos ^2(a+pai)sin^2(a+3pai)/ sin(a-4pai)sin(5pai+a)cos^2(-a-pai)
cos(a+pai/4)=3/5,pai/2
sin(pai-a)cos(2pai-a)tan(-a+pai)/-tan(-a-pai)sin(-pai-a)
已知cosa=-3/5,a属于(pai/2,pai),则cos(pai/4-a)=
求值Cos pai/17 *cos 2pai/17*cos 4pai/17*cos 8pai/17
cos(pai/15)×cos(2pai/15)×cos(3pai/15)×cos(4pai/15)×cos(5pai/15)×cos(6pai/15)×cos(7pai/15)求值
cos(pai/15)×cos(2pai/15)×cos(3pai/15)×cos(4pai/15)×cos(5pai/15)×cos(6pai/15)×cos(7pai/15)求值
sin(pai-a)cos(-8pai-a)=60/169且a属于(pai/4,pai/2)求cosa,sina
sin(a-3pai)cos(pai-a) / cos(pai/2 - a)cos(pai+a)sin(pai/2 + a)
化简:[sin(a+2pai)cos(pai+a)]/[sin(-pai-a)cos(-pai-a)]
化简：sin(2pai-a)cos(pai a)/cos(pai-a)sin(3pai-a)
sin^2(a+pai)-cos(pai+a)*cos(-a)+1
求值:cos(2pai/7)+cos(4pai/7)+cos(6pai/7)pai打不出,不好意思
[tan(pai-a)cos(2pai-a)sin(-a+3pai/2)]/[cos(-a-pai)sin(-pai-a)]=
cos^2A+cos^2(pai/3+A)+cos^2(pai/3-A)pai姐系派化简
(sin(a-pai)cot(a-2pai))/(cos(a-pai)tan(a-2pai))
已知a属于(pai/2,pai),tan(a+pai/4)=1/7,sin a+cos a=?