Determine the domain of f(x) = sqrt(2x + 3).

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Multiple Choice

Determine the domain of f(x) = sqrt(2x + 3).

Explanation:
For a real square root, the expression inside must be nonnegative. So for f(x) = sqrt(2x + 3), require 2x + 3 ≥ 0. Solving gives x ≥ -3/2. This means all real numbers at or to the right of -3/2 are allowed, i.e., the domain is [-3/2, ∞). If x < -3/2, the inside is negative and the square root isn’t real, which is why those values aren’t in the domain. The boundary value -3/2 works because it makes the radicand zero, giving f(x) = 0.

For a real square root, the expression inside must be nonnegative. So for f(x) = sqrt(2x + 3), require 2x + 3 ≥ 0. Solving gives x ≥ -3/2. This means all real numbers at or to the right of -3/2 are allowed, i.e., the domain is [-3/2, ∞). If x < -3/2, the inside is negative and the square root isn’t real, which is why those values aren’t in the domain. The boundary value -3/2 works because it makes the radicand zero, giving f(x) = 0.

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