Evaluate the radical function at the given value of the variable.
-$$f ( x ) = \sqrt { 4 x + 9 }$$
A) $\left( \frac { 9 } { 4 } , \infty \right)$
B) $\left( - \frac { 9 } { 4 } , \infty \right)$
C) $\left[ - \frac { 9 } { 4 } , \infty \right]$
D) $\left( - \infty , - \frac { 9 } { 4 } \right)$

Question

Quizplus · Accepted Answer

We need to find the domain of the function. For the function to be defined, the expression inside the square root must be non-negative. That is,
$$4x+9 \geq 0$$
Solving this inequality, we get 
$$x \geq -\frac{9}{4}$$
Therefore, the domain of the function is $\left[-\frac{9}{4}, \infty \right)$. Hence the correct choice is $\boxed{\textbf{(C)}}$.

Evaluate the Radical Function at the Given Value of the Variable