 will also get a lot of questions on this slide. Useful with respect to school exams and it comes out of this directly comes from application of integration by process. And then we will start taking your problems. Disturb this expression. In this expression take e to the power x minus integral of derivative of f of x which is f dash x into integral of e to the power x which is e to the power x, so they would cancel off. So you don't need to add a result you can use. No the moment you do this you would have done it. So first substitute to x is t. Okay first one. So the second one says t. So this implies 2dx is 1 plus 90 and this has 2dx. See the problem is because of that you should have strictly e to the condition e to the power. So first you should know. So dx is also e to the power t and dx will become e to the power t dt till this is the most of your problem. Now the problem is t and 1 by t square are not related to each other as being derivatives of one another right. So what I am doing is I am going to do this