A sound wave has the from represented in the graph. Which of the following equations represent the graph? Select all that apply
f(x)=5cos(x + pi/4)
f(x)=5sin(x + pi/4)
f(x)=5cos(x + 2pi/4)
f(x)=5sin(x + 2pi/4)
f(x)=5cos(x + 3pi/4)
f(x)=5sin(x + 3pi/4)
