The domain of the function \(f(x) = \sin^{-1}\left(\log_{2} x\right)\) is
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → \(\left[\displaystyle\frac{1}{2}, 2\right]\)
Two conditions are needed: \(\log_{2} x\) must be defined, so \(x \gt 0\), and the argument of \(\sin^{-1}\) must lie in \([-1, 1]\):
\(-1 \le \log_{2} x \le 1\)
Since \(\log_{2}\) is an increasing function, the inequality keeps its direction when we raise 2 to each part:
\(2^{-1} \le x \le 2^{1}\)
\( \displaystyle \frac{1}{2} \le x \le 2 \)
All these values are positive, so the first condition holds too. Hence the domain is \(\left[\frac{1}{2}, 2\right]\).