To determine if \( y = \sqrt{x + 2} - 3 \) is a function, we need to understand the definition of a function. A function assigns exactly one output (value of \( y \)) for each input (value of \( x \)).
Analysis:
-
Domain: The expression \( \sqrt{x + 2} \) is defined for \( x + 2 \geq 0 \) (since you cannot take the square root of a negative number). This implies: \[ x + 2 \geq 0 \implies x \geq -2 \] Thus, the domain of the function is \( x \in [-2, \infty) \).
-
Output for each input: For each value of \( x \) in the domain, there is a unique value of \( y \): \[ y = \sqrt{x + 2} - 3 \] Since the square root function produces exactly one output for each non-negative input, and by subtracting 3, we do not change that uniqueness.
Conclusion:
Yes, \( y = \sqrt{x + 2} - 3 \) is a function, since for each \( x \) in its domain, there is a unique \( y \).