Integration involving complex exponentials

Join the discussion
Ask a follow-up here, or get your own question answered by working scientists, mathematicians and engineers — people, not an autocomplete.
Real named experts · corrections over time · the nuance an AI answer skips
4 replies · 2K views
Jadaav
Messages
175
Reaction score
1

Homework Statement



[itex]\int[/itex][itex][[/itex]( e^x + 4 )/ (4e^x + 1) [itex]][/itex]^2

Homework Equations



No substitutions have been given.

The Attempt at a Solution



I've tried using the method of f' (x)/f (x). But it was in vain.

I haven't been able to do it. I don't really know where to start.
 
Last edited:
Physics news on Phys.org
Jadaav said:

Homework Statement



[itex]\int[/itex][itex][[/itex]( e^x + 4 )/ (4e^x + 1) [itex]][/itex]^2

Homework Equations



No substitutions have been given.

The Attempt at a Solution



I've tried using the method of f' (x)/f (x). But it was in vain.

.. because clearly the numerator is not the derivative of the denominator.

I haven't been able to do it. I don't really know where to start.

Consider the substitution [itex]u = e^x[/itex].
 
  • Like
Likes   Reactions: 1 person
Actually I was thinking about the substitution. But I have one question; an exponential function is not linear. So if I use substitution does it become a linear one ?
 
Jadaav said:
Actually I was thinking about the substitution. But I have one question; an exponential function is not linear. So if I use substitution does it become a linear one ?

No. Your function will become a rational function. You will then be able to integrate it by following the method of partial fractions to separate it into a sum of known integrals.
 
  • Like
Likes   Reactions: 1 person
OK thanks.

I'll start working on it.