1. The problem statement, all variables and given/known data Adjacent antinodes of a standing wave on a string are a distance 15.0cm apart. A particle at an antinode oscillates in simple harmonic motion with amplitude 0.850cm and period 0.0750s. The string lies along the +x - axis and is fixed at x=0. At time t=0, all points on the string are at their minimum displacement. Find the amplitude at a point a distance 3.0cm to the right of an antinode. 2. Relevant equations d^y(x,t) /dx^2 = 1/v^2 . d^2y(x,t)/(dt^2) 3. The attempt at a solution wavlength is 2 x 15 cm = .30m f is 1/T = 13.333 Hz so v = 4 m/s, v^2 = 16 and 1/v^2 is 0.0625 However, I' having trouble getting the second derivative of the wave equation using the point 3.0 cm to the right of the antinode.