NCERT Book Class 12 Maths Differential Equations

9.1 Introduction
In Class XI and in Chapter 5 of the present book, we discussed how to differentiate a given function f with respect to an independent variable, i.e., how to find f (x) for a given function f at each x in its domain of definition. Further, in the chapter on Integral Calculus, we discussed how to find a function f whose derivative is the function g, which may also be formulated as follows:

For a given function g, find a function f such that dy/dx = g(x), where y = f (x) . .. (1)

An equation of the form (1) is known as a differential equation. A formal definition will be given later.

These equations arise in a variety of applications, may it be in Physics, Chemistry, Biology, Anthropology, Geology, Economics etc. Hence, an indepth study of differential equations has assumed prime importance in all modern scientific investigations.

In this chapter, we will study some basic concepts related to differential equation, general and particular solutions of a differential equation, formation of differential equations, some methods to solve a first order - first degree differential equation and some applications of differential equations in different areas.

9.2 Basic Concepts
We are already familiar with the equations of the type:

                    x2 – 3x + 3 = 0                               ... (1)

                    sin x + cos x = 0                             ... (2)

                    x + y = 7                                         ... (3)

Please refer to attached file for NCERT Class 12 Maths Differential Equations