pi=3.14 b=ψ
f(x)是偶函数 =>f(0)=2或-2 =>b-pi/6=pi/2+2k*pi或-pi/2+2k*pi k=0 ,-1,+1,-2 +2 .
=>b=2pi/3+2k*pi 或b=-pi/3+2k*pi
因为0 w=2pi/(pi/2*2)=2
f(x)=-2sin(2x)
pi=3.14 b=ψ
f(x)是偶函数 =>f(0)=2或-2 =>b-pi/6=pi/2+2k*pi或-pi/2+2k*pi k=0 ,-1,+1,-2 +2 .
=>b=2pi/3+2k*pi 或b=-pi/3+2k*pi
因为0 w=2pi/(pi/2*2)=2
f(x)=-2sin(2x)