Original sentence: It arises in fields such as acoustics, Louis Lagrange.[[Image:Spherical wave2.gif|frame|right|== Introduction ==
Edited sentence: Historically, the problem of a vibrating string such as that of a musical instrument was studied by Jean le Rond d'Alembert, Leonhard Euler, Daniel Bernoulli, and  Joseph-Louis Lagrange.It arises in fields such as acoustics, electromagnetics, and fluid dynamics