
Mathematical Method “First Order Differential Equations” Pdf download Chapter 9
A first-order differential equation is a mathematical equation that relates a function of one variable to its derivative. Specifically, a first-order differential equation can be written in the form:
dy/dx = f(x,y)
where y is the unknown function, x is the independent variable, and f is a given function.
The solution to a first-order differential equation is a function y(x) that satisfies the equation for all values of x. Solving a first-order differential equation typically involves finding an expression for y in terms of x by integrating both sides of the equation.
There are various methods for solving first-order differential equations, including separation of variables, integrating factors, and exact equations.
In separation of variables, the equation is rearranged so that all terms involving y appear on one side of the equation and all terms involving x appear on the other side. The resulting equation can be integrated to obtain the solution.
In integrating factors, the equation is multiplied by a function that depends only on x and has the property that the resulting equation can be written in the form (y(x) * g(x))’ = h(x), where g(x) and h(x) are given functions. This form allows the equation to be integrated using the product rule of differentiation.
In exact equations, the equation can be written in the form M(x,y)dx + N(x,y)dy = 0, where M and N are given functions, and the solution is obtained by finding a function F(x,y) such that Fx = M and Fy = N.
First-order differential equations have numerous applications in science and engineering, including modeling of population growth, radioactive decay, and chemical reactions.