Differential equations are mathematical equations that relate a function with one or more of its derivatives. In many cases, studying a function without understanding its derivatives would be pointless, and so differential equations provide a way of understanding how a function changes as its inputs change.
There are many different types of differential equations, but they can generally be classified into two categories: linear and nonlinear. Linear differential equations are those whose solutions can be written as a linear combination of the derivatives of the function, while nonlinear differential equations are those whose solutions cannot be written in this form.
In general, differential equations are very difficult to solve, and so most work in this area is focused on finding approximate solutions. Numerical methods are often used to find these solutions, and there are a variety of different methods that can be used depending on the specific equation and the desired accuracy.
These equations can be used to model a variety of physical phenomena, such as the motion of objects, the spread of diseases, and the flow of heat. Differential equations can be difficult to solve, but there are a number of methods that can be used to find solutions. In many cases, a numerical approach is taken, where the equation is approximated using a computer.