已知函数f(x)=Asin(wx+fai)(其中x属于R,A>0,w>0,-pai/2

由图知,A=1
x=-1时,-ω+ψ=0
x=3时,3ω+ψ=π
∴ω=π/4,ψ=π/4
验证：x=1时,y=sin[(π/4)+(π/4)]
=sin(π/2)
=1
x=5时,y=sin[(π/4)*5+(π/4)]
=sin(3π/2)
=1
∴f(x)=sin[(π/4)x+(π/4)]
通过上述计算,知f(-1)=0,f(1)=1,f(3)=0