You want the limit:
...
.
So I'm using the Rydberg formula in my Astronomy class but I am really confused as to how I am supposed to subtract 1-1/infinity and get a numerical answer without exponents. I understand how the formula works, but I have been out of math classes for so long that I have actually forgot how to do this. If anyone can help me out a little, I would greatly appreciate it.
Thanks!