Bilateral version, i.e., if calculated from \(-\infty \) to \(+\infty \) , of Laplace transforms may be seen as a more general case of Fourier transform. Laplace transform is calculated as complex integral of complex variable, while Fourier transform is calculated as complex integral of real variable. Arguably, most practical application of Laplace transform in the engineering field is to convert some categories of differential equations into ordinary polynomial equations. By doing so, basic algebra techniques are used to derive solutions of these differential equations.