题目呢
f(x)=2asinxcosx+2bcos²x,且f(0)=8,f(π/6)=12
求得b=4
2sinxcosx=sin2x
2cos²x=cos2x +1
f(x)=asin2x+b（cos2x +1）
f(0)=2b=8
b=4
f(π/6)=a√3/2 + b3/2=a√3/2 +6=12
a√3/2 =6
a=4√3