Discover the answers you need at Westonci.ca, a dynamic Q&A platform where knowledge is shared freely by a community of experts. Connect with a community of professionals ready to help you find accurate solutions to your questions quickly and efficiently. Join our platform to connect with experts ready to provide precise answers to your questions in different areas.

Which function has a domain of [tex]x \geq 5[/tex] and a range of [tex]y \leq 3[/tex]?

A. [tex]y = \sqrt{x - 5} + 3[/tex]
B. [tex]y = \sqrt{x + 5} - 3[/tex]
C. [tex]y = -\sqrt{x - 5} + 3[/tex]
D. [tex]y = -\sqrt{x + 5} - 3[/tex]


Sagot :

To find the function that has a domain of [tex]\( x \geq 5 \)[/tex] and a range of [tex]\( y \leq 3 \)[/tex], we'll analyze each given function separately:

### 1. [tex]\( y = \sqrt{x-5} + 3 \)[/tex]

Domain:
To ensure the expression under the square root is non-negative, we need:
[tex]\[ x - 5 \geq 0 \][/tex]
[tex]\[ x \geq 5 \][/tex]
Hence, the domain is [tex]\( x \geq 5 \)[/tex].

Range:
For [tex]\( x \geq 5 \)[/tex], [tex]\( \sqrt{x - 5} \)[/tex] will be non-negative (i.e., [tex]\( \sqrt{x-5} \geq 0 \)[/tex]). Consequently,
[tex]\[ y = \sqrt{x - 5} + 3 \geq 0 + 3 = 3 \][/tex]
Thus, the range is [tex]\( y \geq 3 \)[/tex].

This does not fit our required range of [tex]\( y \leq 3 \)[/tex].

### 2. [tex]\( y = \sqrt{x+5} - 3 \)[/tex]

Domain:
To ensure the expression under the square root is non-negative, we need:
[tex]\[ x + 5 \geq 0 \][/tex]
[tex]\[ x \geq -5 \][/tex]
Hence, the domain is [tex]\( x \geq -5 \)[/tex].

Range:
For [tex]\( x \geq -5 \)[/tex]:
[tex]\[ \sqrt{x + 5} \geq 0 \][/tex]
Thus,
[tex]\[ y = \sqrt{x + 5} - 3 \geq 0 - 3 = -3 \][/tex]
So the range will be [tex]\( y \geq -3 \)[/tex].

This does not fit our required range of [tex]\( y \leq 3 \)[/tex].

### 3. [tex]\( y = -\sqrt{x-5} + 3 \)[/tex]

Domain:
To ensure the expression under the square root is non-negative, we need:
[tex]\[ x - 5 \geq 0 \][/tex]
[tex]\[ x \geq 5 \][/tex]
Hence, the domain is [tex]\( x \geq 5 \)[/tex].

Range:
For [tex]\( x \geq 5 \)[/tex]:
[tex]\[ \sqrt{x - 5} \geq 0 \][/tex]
Thus,
[tex]\[ y = -\sqrt{x - 5} + 3 \leq 0 + 3 = 3 \][/tex]
So the range will be [tex]\( y \leq 3 \)[/tex].

This fits our required range of [tex]\( y \leq 3 \)[/tex] perfectly.

### 4. [tex]\( y = -\sqrt{x+5} - 3 \)[/tex]

Domain:
To ensure the expression under the square root is non-negative, we need:
[tex]\[ x + 5 \geq 0 \][/tex]
[tex]\[ x \geq -5 \][/tex]
Hence, the domain is [tex]\( x \geq -5 \)[/tex].

Range:
For [tex]\( x \geq -5 \)[/tex]:
[tex]\[ \sqrt{x + 5} \geq 0 \][/tex]
Thus,
[tex]\[ y = -\sqrt{x + 5} - 3 \leq 0 - 3 = -3 \][/tex]
So the range will be [tex]\( y \leq -3 \)[/tex].

This does not fit our required range of [tex]\( y \leq 3 \)[/tex].

### Conclusion:

The only function that satisfies both the domain [tex]\( x \geq 5 \)[/tex] and the range [tex]\( y \leq 3 \)[/tex] is:

[tex]\[ y = -\sqrt{x-5} + 3 \][/tex]