Nonlinear equations are those that do not form a straight line. They may form a bell curve, S-curve, or any other nonlinear shape on a graph. These equations have a variable slope and are more complicated as compared to linear equations. A nonlinear equation has a degree of two or greater than two, but not less than two. As the value of the degree increases, so does the curvature of the graph. In general, nonlinear equations cannot be solved analytically. Two criteria can be taken into account when choosing a method for solving nonlinear equations, namely, method convergence and the cost of calculating of the method. Nonlinear equations are utilized for managing projects and making predictions. Some examples of nonlinear equations include S-curve graphs, regression analysis, and logarithmic scales. Important numerical methods for solving nonlinear equations include first order methods, Newton-Raphson method, and bisection method. This book explores all the important aspects of the numerical methods used for solving nonlinear equations. It is a resource guide for experts as well as students.