正弦函数化简方法
∵y=Asin(wx+φ)（A>0，w>0，|φ|
∴A=√2，且sin（2w+φ)=1
又最高点到相邻最低点之前的曲线与x轴交于点(6，0)
∴T=4x4=16=2π/w
∴w=2π/16=π/8
∵2w+φ=π/2
∴φ=π/4
∴函数解析式为y=√2sin(π/8x+π/4)
f(x)=sin(2x+π/4)+cos(2x-π/4)
=sin(2x+π/4)+cos[-π/2+(π/4+2x)]
=sin(2x+π/4)+sin(2x+π/4)
=2sin(2x+π/4)
