Question #N2
The function $f(x)$ is defined by $f(x) = \frac{x^2 - 1}{x - 1}$. For what value(s) of $x$ is $f(x)$ undefined?
A. 1 only
B. -1 only
C. 0 only
D. 1 and -1
Correct Answer is: A
A function is undefined when the denominator equals zero. In this case, the denominator is $x-1$, which is zero when $x=1$. Therefore, $f(x)$ is undefined when $x=1$.