Help with problem

[ijabbott]

(08-05-2019 12:32 PM)Marcel Wrote:  Hi!
For myself I prefert to do a simplification before using de domain function!
After that, the domain is OK…
Choice A with -5.
Marcel

Technically, doesn't simplifying \(\frac{x-5}{x^2-25}\) to \(\frac{1}{x+5}\) change the domain? I know the original approaches \(\frac{1}{10}\) in the limit as \(x \to 5\), but it should probably have an open circle at \((5, \frac{1}{10})\).