将f(0)=1,f(π/3)=-1/2+根号3/2 代入函数中,得
f(0)=2a-1=1
f(π/3)=(1/2)a-1+(根号3/4)b =-1/2+(根号3)/2
解得a=1,b=2
所以f(x)=2cos^2x+2sinxcosx-1
=cos2x+sin2x
=(根号2)sin(2x+π/4)
当-π/2+2kπ
将f(0)=1,f(π/3)=-1/2+根号3/2 代入函数中,得
f(0)=2a-1=1
f(π/3)=(1/2)a-1+(根号3/4)b =-1/2+(根号3)/2
解得a=1,b=2
所以f(x)=2cos^2x+2sinxcosx-1
=cos2x+sin2x
=(根号2)sin(2x+π/4)
当-π/2+2kπ