因A>0,
故sinC=cosA
故C≠π/2由正弦定理
a/sinA=b/sinB
即b/a=sinB/sinA=cosA/cosB
故sinA·cosA=sinB·cosB
即sin2A=sin2B
故2A+2B=π
或A=B
但当2A+2B=π即A+B=π/2时
C=π/2不合题意
故A=B
因sinC=cosA=sin(π/2-A)
故C=π/2-A
或C+π/2-A=π
但当C=π/2-A,即A+C=π/2时,B=π/2
不合题意
故C+π/2-A=π
解之
A=B=π/6,C=2π/3故f(x)=sin(2x+A)+cos(2x-C/2)
=sin(2x+π/6)+cos(2x-π/3)
=√3sin(2x)+cos(2x)
=2sin(2x+π/6)剩下自己做了
问的啥