x∈[0,π/4]∴2x+π/6∈[π/6,π/2+π/6]
∴2x+π/6=π/6时,即x=0时,f(x)=2sinπ/6=1最小;
2x+π/6=π/2时,即x=π/6时,f(π/6)=2sinπ/2=2最大.