F(x)=|cos2x+sin2x+Ax+B|=|
sin(2x+
2
)+Ax+B|,π 4
(1)若F(x)是周期函数,F(x+π)=F(x),即|
sin(2x+
2
)+Ax+B|=|π 4
sin(2π+2x+
2
)+Ax+Aπ+B|,π 4
可得A=0,B为任意实数;
(2)∵0≤x≤
,∴3π 2
≤2x+π 4
≤π 4
,13π 4
∴-1≤
sin(2x+
2
)≤π 4
,
2
当A=0,B=-
时,
2
+1≥F(x)=|
2
sin(2x+
2