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**1. Homework Statement**

Consider the sinusoidal wave in the figure, with the wave function below.

At a certain instant, let point A be at the origin and point B be the first point along the x axis where the wave is 60.0° out of phase with point A. What is the coordinate of point B?

y = (15.0 cm) cos(0.157x - 50.3t)

and I am not allowed to post the image but heres some helpful information:

its a cosine graph, and [tex]\lambda[/tex] = 40 cm, T = 0.125 s, f = 8.00 hz, k = 0.157 rads/cm

**2. Homework Equations**

Some equations that I have are:

k=2[tex]\pi[/tex]/[tex]\lambda[/tex]

v=[tex]\lambda[/tex]*f

y=Asin(kx-[tex]\omega[/tex]t)

**3. The Attempt at a Solution**

What I have tried so far is:

y=15*sin((.157)x-(50.3)t + [tex]\pi[/tex]/3)

The example says " The vertical position of an element of the medium at t = 0 and x = 0 is also 15.0 cm "

The only problem is that I am really stuck and I cannot seem what to set the 60.0[tex]\circ[/tex] equal to. Help would be much appreciated! Thank you!