Question #N498
The function $f(x) = \frac{1}{x^2 + 1}$ is defined for all real numbers. What is the value of $f(\frac{1}{2})$?
A. $\frac{1}{5}$
B. $\frac{2}{5}$
C. $\frac{4}{5}$
D. $\frac{5}{4}$
Correct Answer is: C
Substituting $x = \frac{1}{2}$ into the function, we get: $f(\frac{1}{2}) = \frac{1}{(\frac{1}{2})^2 + 1}$. Simplifying the denominator, we have: $f(\frac{1}{2}) = \frac{1}{\frac{1}{4} + 1} = \frac{1}{\frac{5}{4}} = \frac{4}{5}$.