1. The problem statement, all variables and given/known data What is the longest wavelength for standing waves on a 254.0 cm long string that is fixed at both ends? 2. Relevant equations 3. The attempt at a solution When x = L (length of string): k(n) = n*pi / L wavelength (n) = n*pi / k(n) I got the answer, I just don't understand why these equations are used in my textbook to find this particular answer.