- #1
avikarto
- 56
- 9
For some small parameter ##\epsilon##, how would one go about making an approximation such as ##\sqrt{k^2-\epsilon^2}\approx k-\frac{\epsilon^2}{2k}##? I was thinking that these types of approximations came from truncating Taylor series expansions, but I can't see how it would be obvious which parameter one would differentiate with respect to, a priori, or what value to expand about. Could someone please explain the general method for making such approximations? Thanks!