 Hello and welcome to the session. I am Deepika here. Let's discuss a question which says integrate the following function, x sign x. Let us first understand integration by parts. Now this method is quite useful in integrating products of functions. Now if we have to integrate two functions, say fx and gh, then the integral of fx, gh. So let us see fx as a first function and gh as a second function. So this is equal to first function that is fx the second function that is integral of gh. Function coefficient of the first function that is f dash x integral of the second function that is integral of gh. We will take the help of this key idea to solve the above question. So let's solve the solution. Now we have to integrate first function. Usually x then we take it as a first function. So according to our key idea integral of function that is n function that is integral of sin x dx initial coefficient of the second function. The process of differentiation and integration are inverses of each other as cos x because integral of cos x is minus x cos x