 and exponentials)
  and exponentials)
There are a few more exotic cases.  Suppose we wish to evaluate   .  The following shows the process.
 .  The following shows the process.
  
 
Here, we let   so that
  so that   and the intgral
becomes
  and the intgral
becomes
  
 
Another common substitution is the let the power in an exponential be u.
  
 
where we have used the substitution   .
 .