已知函数f(x)=cos2的平方x+根号3sinxcosx-1/2.

（1）f(x)=（cosx）^2+√3sinxcosx-1/2=1/2(1+cos2x)+√3/2sinxcosx-1/2=1/2cos2x+√3/2sin2x
=sin(2x+30°),f(x)最大值为1,此时x=30°=派/6
（2）由cos(a-b)=4/5,cos(a+b)=-3/5,0

f(x)=(√3/2)sin2x+(1/2)cos2x=sin(2x+π/6)
(1)0<=x<=π/2，π/6<=2x+π/6<=7π/6，当2x+π/6=π/2，即x=π/3，f(x)的最大值f(π/3)=sinπ/2=1。
(2)sin(a-b)=3/5，sin(a+b)=4/5。
f(a-π/12)=sin2a=sin[(a+b)+(a-b)]=sin(a+b)cos(a-b)+cos(a+b)sin(a-b)=(4/5)*(4/5)+(-3/5)*(3/5)=7/25

f(x)=cosx的平方+根号3sinxcosx-1/2吗？