已知函数
f (
x)=

sin
ωx+

(
ω>0,
x∈R),且函数
f (
x) 的最小正周期为π.
(Ⅰ)求函数
f (
x) 的解析式;
(Ⅱ)在△
ABC中,角
A,
B,
C所对的边分别为
a,
b,
c.若
f (
B)=1,

,
且
a+
c=4,试求
b2的值.
解:(1)

,3分
又

,

, 5分

; 6分
(2)

,

,
解得

,又

是

的内角,

; 9分
而

,

, 11分
又

,

,

. 14分
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