(sin(a+b)sin(a-b)\sina^2cosb^2=1-(tanb\tana)^2

sin a-sin b等于 证明sin(a+b)sin(a-b)=sin^2 a-sin^2 b, 如何证明sin(a+b)sin(a-b)=sin*a-sin*b (*为平方) 求证恒等式sin(A+B)sin(A-B)=sin²A-sin²B 求证:sin(a+b)sin(a-b)=sin^2a-sin^2b sin a+sin b 等于什么 怎样证明/sin a +sin b/ 【证明】Sin A+sin B=2Sin 22 在三角形abc中 sin^A+sin^B+sin^C 已知sin(a)=2sin(b)求sin(a/2)/sin(b/2)的值. 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 sin(a+b)sin(a-b)=sin2a-sin2b求证 求证：sin(A+B)sin(A-B)=sinAsinA-sinBsinB sin（a-b）=sin（a+b）吗? SIN(B-A)=-SIN(A-B)为啥 sin(A-B)等于啥子. sin(A-B)等于多少? sin(a+b)等于什么?