Question #N827
The function $f(x)$ is defined by $f(x) = \frac{x^2 - 9}{x - 3}$. For what value of $x$ is $f(x)$ undefined?
A. -3
B. 0
C. 3
D. 9
Correct Answer is: C
The function $f(x)$ is undefined when the denominator of the fraction is equal to zero. The denominator is $x - 3$, and this is equal to zero when $x = 3$. Therefore, $f(x)$ is undefined for $x = 3$.