1. The problem statement, all variables and given/known data A transverse wave on a cord is given by D(x, t) = 0.19sin(2.9x - 35t), where D and x are in m and t is in s. 1) At t = 8.6*10^-2 s, what is the displacement of the point on the cord where x = 0.62 m? 2) At t = 8.6*10^-2 s, what is the velocity of the point on the cord where x = 0.62 m? 2. Relevant equations given displacement ---> D(x, t) = 0.19sin(2.9x - 35t) 3. The attempt at a solution I didnt have any trouble finding the displacement of the wave along the cord (-0.18m) as all I had to do was plug in the given values of x and t, then make sure my calculator was in radians. The velocity is where I ran into problems. I figured it shouldnt be any harder than taking the derivative of the given equation, then once again plugging in the supplied values. However, I did not come up with the correct answer, and I not sure if I simply differentiated incorrectly or if that is not even the correct approach. Heres my work: 0.19sin(2.9x - 35t) ---> ∂D/∂t = 0.19cos(2.9x - 35t) * (2.9 - 35t) ∂D/∂t = 0.19cos(2.9x - 35t) * (2.9 - 3.01) = (-0.11)*0.19cos(2.9x - 35t) ∂D/∂t = -0.0209cos(2.9x - 35t) ∂D/∂t = -0.0209cos(-1.212) ∂D/∂t = -0.007338 m/s But, like I said, ∂D/∂t =/= -0.007338 m/s Any help would be greatly appreciated.