Get personalized answers to your unique questions on IDNLearn.com. Get accurate answers to your questions from our community of experts who are always ready to provide timely and relevant solutions.

Find the domain of the function.

[tex]f(x)=\frac{1}{\sqrt{x+3}}[/tex]

A. [tex]x \leq 3[/tex]
B. no solutions
C. [tex]x \ \textgreater \ -3[/tex]
D. [tex]x \geq -3[/tex]


Sagot :

To determine the domain of the function [tex]\( f(x) = \frac{1}{\sqrt{x+3}} \)[/tex], we need to consider where the function is defined and where it makes sense mathematically.

### Step-by-Step Solution:

1. Identify restrictions due to the square root:
- The square root function, [tex]\( \sqrt{u} \)[/tex], is only defined for values [tex]\( u \geq 0 \)[/tex]. For the expression [tex]\( \sqrt{x + 3} \)[/tex] to be defined, we must have:
[tex]\[ x + 3 \geq 0 \][/tex]
- Solving for [tex]\( x \)[/tex]:
[tex]\[ x \geq -3 \][/tex]

2. Identify restrictions due to the denominator:
- The function [tex]\( f(x) = \frac{1}{u} \)[/tex] is undefined when [tex]\( u = 0 \)[/tex] because division by zero is undefined. For our function [tex]\( f(x) = \frac{1}{\sqrt{x + 3}} \)[/tex], the denominator is [tex]\( \sqrt{x + 3} \)[/tex]. We need to ensure that:
[tex]\[ \sqrt{x + 3} \neq 0 \][/tex]
- Solving for [tex]\( x + 3 \neq 0 \)[/tex]:
[tex]\[ \sqrt{x + 3} \neq 0 \implies x + 3 \neq 0 \implies x \neq -3 \][/tex]

By combining these two conditions:
- [tex]\( x + 3 \geq 0 \)[/tex] (or [tex]\( x \geq -3 \)[/tex])
- [tex]\( x \neq -3 \)[/tex].

We find that:
- [tex]\( x \)[/tex] must be greater than [tex]\(-3\)[/tex] for the function to be defined.

### Writing the Domain:
The domain of [tex]\( f(x) = \frac{1}{\sqrt{x+3}} \)[/tex] in interval notation is:
[tex]\[ (-\infty, -3) \][/tex]

Thus, based on these conditions, the domain of the function is:
[tex]\( x > -3 \)[/tex]

Or formally written:
[tex]\( (-\infty, -3) \)[/tex]