ABSTRACT
The problem is illustrated graphically in Figure 3.14. The functions f(x, y) and g(x,y) may be algebraic equations, transcendental equations, the solution of differential equations, or any nonlinear relationships between the inputs x andy and the outputsf(x,y) and g(x, y). Thef(x, y) = 0 and g(x, y) = 0 contours divide the xy plane into regions where f(x,y) and g(x,y) are positive or negative. The solutions to Eq. (3.168) are the intersections of the f(x, y) = g(x, y) = 0 contours, if any. The number of solutions is not known a priori. Four such intersections are illustrated in Figure 3.14. This problem is considerably more complicated than the solution of a single nonlinear equation.
