△ABC的三个内角A,B,C所对的边分别为a,b,c,asin Asin B+bcos2A=
a,则
=( )
A.2
B.2
C.
D.![]()
△ABC的三个内角A,B,C所对的边分别为a,b,c,asin Asin B+bcos2A=
a,则
=( )
A.2
B.2
C.
D.![]()
解析:∵asin Asin B+bcos2A=
a,
由正弦定理可得sin2Asin B+sin Bcos2A=
sin A,
∴sin B=
sin A,即
=
.
答案:D