1. The problem statement, all variables and given/known data If the displacement of a tight string is represented by y(x,t)= Acos(2∏/λ(x-vt)) Determine an expression for the velocity vy at which a section of the string travels. What is the maximum value of Vy? When is this maximum value greater than the wave propagation speed v? 3. The attempt at a solution I started by differentiating the equation to get Vy = -A(2∏/λ)vsin((2∏/λ)(x-vt)) I then said that Vy would reach a maximum when sin((2∏/λ)(x-vt)) = 1 but I don't think this is right. Any help would be appreciated. Thank you.