化简sin^2(a)sin(3a)+cos^2(a)cos(3a)
来源：学生作业帮助网 编辑：六六作业网 时间：2025/01/24 02:10:45
化简sin^2(a)sin(3a)+cos^2(a)cos(3a)化简sin^2(a)sin(3a)+cos^2(a)cos(3a)化简sin^2(a)sin(3a)+cos^2(a)cos(3a)s
化简sin^2(a)sin(3a)+cos^2(a)cos(3a)
化简sin^2(a)sin(3a)+cos^2(a)cos(3a)
化简sin^2(a)sin(3a)+cos^2(a)cos(3a)
sin3a=sin(2a+a)=sin2acosa+cos2asina=(2sinacosa)cosa+(cos²a-sin²a)sina
=2sinacos²a+sinacos²a-sin³a=3sinacos²a-sin³a
cos3a=cos(2a+a)=cos2acosa-sin2asina=(cos²a-sin²a)cosa-(2sinacosasina)
=cos³a-sin²acosa-2sin²acosa=cos³a-3sin²acosa
原式
=(3sinacos²a-sin³a)*sin²a+cos²a(cos³a-3sin²acosa)
=3sina³cos²a-(sina)^5+(cosa)^5-3sin²acos³a
=(cosa)^5-(sina)^5
化简：sin^2a+sin^2(a-180/3)+sin^2(a+180/3)
化简；sin^2 A+sin^2(A-π/3)+sin^2(A+π/3)
化简sin^2A+sin^(A-π/3)+sin(A+π/3)
sin^2(-a)化简
sin a+sin 2a +sin 3a +...+sin na怎么求和?
sin a+sin 2a +sin 3a +...+sin na怎么求和?
化简sin(2π-a)sin(π+a)coa(-π-a)除以sin(3π-a)cos(π-a)
化简 sin(2π-a)sin(π+a)cos-π-a) / sin(3π-a)cos(π-a)
化简:sin(-a)cos(2π+a)sin(-a-π)
化简Sin A + Sin 2A / 1+cos A +
化简sin^(a-30°)+sin^(a+30°)-sin^a化简sin^2(a-30°)+sin^2(a+30°)-sin^2a
化简sin^2(a)sin(3a)+cos^2(a)cos(3a)
化简：sin(2pai-a)cos(pai a)/cos(pai-a)sin(3pai-a)
3 在三角形ABC中,已知（a2+b2）sin（A-B）=（a2-b2）sin(A+B) 求证：ABC是等腰或直角三角形(a^2+b^2)sin(A-B)=(a^2-b^2)sin(A+B),(sin^A+sin^B)sin(A-B)=(sin^A-sin^B)sin(A+B) sin^A*(sin(A+B)-sin(A-B))=sin^B*(sin(A-B)+sin(A+B)) sin^A*2c
化简sin(-A-2派)
化简sin(2π+a)
化简sin(π+a)+sin(2π+a)+sin(3π+a)+……sin(kπ+a)K为奇数和K为偶数两个答案,
化简（sin(a-b)-2sin a cos b）/2sin a sin b +coa(a+b)