I have been informed that on March 7th from 6:00am to 6:00pm Central Time Lamar University will be doing some maintenance to replace a faulty UPS component and to do this they will be completely powering down their data center.
Unfortunately, this means that the site will be down during this time. I apologize for any inconvenience this might cause.
Paul
February 18, 2026
Section 3.4 : The Definition of a Function
15. Determine the domain of the following function.
\[f\left( x \right) = \frac{1}{{{x^2} - 25}}\] Show SolutionRecall that the domain is simply all the values of \(x\) that we can plug into the function and the resulting function value will be a real number.
In this case we have a rational expression where the numerator is a constant (and so won’t cause any problems for any value of \(x\)) and the denominator is a polynomial.
So, we need to avoid division by zero for this problem. We will get division by zero at,
\[{x^2} - 25 = 0\hspace{0.25in} \to \,\,\ {x^2} = 25\hspace{0.25in} \to \,\,\ x = \pm 5\]Therefore, the domain for this function is all real numbers except \(x = \pm 5\) .