ABSTRACT
A first-order differential equation is integrated once to obtain a solution, and a second order equation is integrated twice, and so on. Many situations occur in engineering, science and economics which can be modelled as differential equations, thereby providing solutions to complex problems. This chapter discusses differential equations involving direct integration and first-order linear differential equations. It provides examples of differential equations in science and engineering and illustrates linear differential equations with constant coefficients. A discussion on simple harmonic motion is also provided.
