已知函数f(x)=3sin^2x+2根号3sinxcosx+5cos^2x

f(x)=3sin^2x+2根号3sinxcosx+5cos^2x
=3sin^2x+√3sin2x+5cos^2x-4cos^x-4sin^2x+4
=2sin(30+2x)+4
T=∏
最大值为 6
2sin(30+2a)+4=5
sin(30+2a)=1/2
30+2a=30 30+2a=150
a=0 a=60
tana=√3