化简求sin^2(a-π/3)+sin^2(a+π/3)+sin^2a

化简求sin^2(a-π/3)+sin^2(a+π/3)+sin^2a 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 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) [sin(a-6π)cos(7π/2-a)]/[sin(3π+a)+sin(a-π）】= sin（-19π/6）=?已知[3Sin(π+a)+Cos(π-a)]/4Sin(-a)-Sin(5π/2+a)=2，求tan a 已知sin(3π+a)=2sin[(3π/2)+a],求sin^2a+sin2a的值 已知sin(3π+a)=2sin(3π/2+a),sin^2a+sin2a = sin((3π)/3-a)=sin(π+(1/2-a))=-(sin(1/2-a))＝-cosa 化简:sin(-a)cos(2π+a)sin(-a-π) sin(3π／2+a)等于多少 sin(3π/2-a)等于几? sin(3Π/2+a)等于什么? 1- sin(2π/3 - a)/sina 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,