f(x)=2sin^2(wx+π/4)+2(cos^2wx)=1-cos(2wx+π/2)+cos(2wx)+1=sin(2wx)+cos(2wx)+2
=√2 sin(2wx+π/4)+2
兩個相鄰的最低點之間的距離=T=2π/2w=2π/3,所以w=3/2
f(x)=√2 sin(3x+π/4)+2
（1）f(x)的最大值2+√2
此時sin(3x+π/4)=1,3x+π/4=π/2+2kπ,x=π/12+2/3 kπ, k=1,2,3...仔細點y=f（x）=√2 sin(3x+π/4)+2右平移π/8個單位長度√2 sin(3(x-π/8)+π/4)+2=√2 sin(3x-π/8)+2沿y軸對稱后得到g（x）=√2 sin(π/8-3x)+2 = - √2 sin(3x-π/8)+2遞減區(qū)間-π/2+2kπ<3x-π/8<π/2+2kπ，則-π/8+2/3kπ