00:01
This problem is going to be a cautionary tail in evaluating integrals of the form.
00:07
It's an improper integral growing from minus infinity to infinity.
00:12
This is going to illustrate why we really need to break this up with a point in between.
00:18
So suppose we were trying to evaluate the integral from minus infinity to infinity of this function, it's going to converge if and only if, say, splitting it up between zero.
00:30
Those two integrals converge.
00:31
So let's see what happens for this integral.
00:37
Here we should just be able to evaluate this directly by substitution.
00:46
So if i do that, how do my limits change? well, the lower limit is one.
00:51
The upper limit is still going to be infinity.
00:54
I'm replacing 2x dx by du and x squared plus 1 by u...