To find \((fg)(x)\), we need to multiply the two functions \(f(x)\) and \(g(x)\):
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Given Functions:
- \(f(x) = \sqrt{x - 1}\)
- \(g(x) = 3x - 1\)
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Calculating \((fg)(x)\): \[ (fg)(x) = f(g(x)) = f(3x - 1) \] Substituting \(g(x)\) into \(f\): \[ f(3x - 1) = \sqrt{(3x - 1) - 1} = \sqrt{3x - 2} \]
Therefore, \((fg)(x) = \sqrt{3x - 2}\).
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Finding the Domain of \((fg)(x)\): The expression under the square root must be non-negative: \[ 3x - 2 \geq 0 \] Solving this inequality: \[ 3x \geq 2 \quad \Rightarrow \quad x \geq \frac{2}{3} \]
Thus, the domain of \((fg)(x)\) is \(x \geq \frac{2}{3}\).
So, the correct response is: \[ (fg)(x) = \sqrt{3x - 2} \] and the domain of \((fg)(x)\) is \(x \geq \frac{2}{3}\).
Since none of the options provided correspond to this analysis directly:
- If \(\sqrt{3x - 2}\) is included in the choices, that is the right function.
- The domain being constraints related to \((-\infty, \infty)\) or other values does not apply according to our findings.
If you have any further options or need clarification, please let me know!