## Algebra and Trigonometry 10th Edition

Example 1: $f(x)=\frac{x+5}{x^2+8}$ Example 2: $f(x)=\frac{x+1}{x-15}$
Example 1: make sure that the denominator is different than $0$ for any $x$ in the set of real numbers. Example 2: make sure that the denominator is equal to $0$ when $x=15$