Finding Limit for Equation: Step-by-Step Guide

[Icheb]

I'm trying to find a limit for this equation:

http://www.formulabin.com/formula/63540850c94efe3e011e283862cc0939

Now I understand I can factor (1-1/k^2) and look for cancellation, but I just can't figure out how to do that in this case.

 

[Fermat]

Do the (a² - b²) = (a-b)(a+b) bit, then substitute in values of k and write down the first few terms multiplied together.
You will see the cancelling out.