1. ## Integration

I was searching videoes on laplace transfroms and came across this form of integration. My question is in what math class do they teach you this form of integration, complexifying the integral.

YouTube - Complexifying the Integral (Arthur Mattuck, MIT)

2. You can do the integration of e^x*cosx or e^-x*cosx by using the integration by parts, where the original integration appears again. To avoid this, complexificaion method is used, which is easier than the other method. In place of cosx, if you have sinx , still you can use this method. Only difference is that in the final answer, you have to choose the imaginary part for the answer.

3. Originally Posted by 11rdc11
I was searching videoes on laplace transfroms and came across this form of integration. My question is in what math class do they teach you this form of integration, complexifying the integral.

YouTube - Complexifying the Integral (Arthur Mattuck, MIT)

I suppose it is in calculus I class: you only need to know the basics of integration and complex numbers. It's a nice trick, pretty standard among many teachers, but completely (and inexplicably so) unknown or unused among many others.

Tonio

4. Yes I did it by integration by parts but thought it was a lot easier with that little trick. I thought maybe in calc 2 where I was taught different techniques on how to integrate but none of my calc classes ever dealt with complex numbers.