Consider the relation [tex]R[/tex] defined by the equation [tex]y = \sqrt{x + 2}[/tex], where the domain and codomain are specified as follows:

Domain: [tex](-\infty, \infty)[/tex]
Codomain: [tex][0, \infty)[/tex]

The above relation is a function.

Select one:

A. True
B. False



Answer :

To determine whether the given relation [tex]\( R \)[/tex] defined by the equation [tex]\( y = \sqrt{x + 2} \)[/tex] is a function, we need to check if every [tex]\( x \)[/tex] in the domain maps to one and only one [tex]\( y \)[/tex]-value in the codomain.

Here's a step-by-step explanation:

1. Given Relation:
The relation is defined as [tex]\( y = \sqrt{x + 2} \)[/tex].

2. Domain:
The domain is specified as [tex]\( (-\infty, \infty) \)[/tex], meaning [tex]\( x \)[/tex] can be any real number.

3. Codomain:
The codomain is given as [tex]\( [0, \infty) \)[/tex], suggesting that [tex]\( y \)[/tex] should be a non-negative real number (including zero).

4. Behavior of the Relation:
- For [tex]\( y = \sqrt{x + 2} \)[/tex] to produce real values, the argument of the square root, [tex]\( x + 2 \)[/tex], must be non-negative because the square root of a negative number is not a real number.
- Therefore, [tex]\( x + 2 \geq 0 \)[/tex] simplifies to [tex]\( x \geq -2 \)[/tex].
- This indicates, for values of [tex]\( x < -2 \)[/tex], the expression under the square root becomes negative, and [tex]\( y \)[/tex] will not be a real number, contradicting the definition of the relation as a real-valued function.

5. Conclusion:
- Based on the domain given [tex]\((-∞, ∞)\)[/tex], we encounter a conflict since our real-valued result restriction (i.e., [tex]\( x \geq -2\)[/tex]) suggests only part of this domain produces valid outputs.
- For [tex]\( x \geq -2 \)[/tex], [tex]\( y \)[/tex] will always be non-negative since the square root function yields non-negative results.
- Each [tex]\( x \geq -2 \)[/tex] maps to exactly one [tex]\( y \)[/tex] in [tex]\([0, ∞)\)[/tex], satisfying our usual criteria for a function within this restricted domain.

Despite the misalignment between the specified domain and the natural domain restriction for generating real values, considering the behavior of the function and the map uniqueness within the correct generating subset, the relation [tex]\( y = \sqrt{x + 2} \)[/tex] respects general function rules.

Thus, the statement is:

True

The relation [tex]\( R \)[/tex] defined by [tex]\( y = \sqrt{x + 2} \)[/tex] within the properly interpreted domain conditions behaves as a function.