You might be most familiar with sonography's role in the field of obstetrics to produce an ultrasound image of an unborn baby. Sonography is also used to analyze tissues and organs of the body, such as the heart, eyes and abdomen.
Etymology: Pierre S. de Laplace, French physicist, 1749-1827. a principle of physics that the tension on the wall of a sphere is the product of the pressure times the radius of the chamber and the tension is inversely related to the thickness of the wall.
So for instance, Laplaceâs equation is elliptic, the heat equation is parabolic, and the wave. equation is hyperbolic. It is useful to classify equations because the solution techniques, and properties of the solutions are diï¬erent, depending on whether the equation is elliptic, parabolic, or hyperbolic.