The domain of \(f(x) = \cos^{-1}7x\) is:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → \(\left[-\displaystyle\frac{1}{7}, \frac{1}{7}\right]\)
The domain of \(\cos^{-1}\) is [−1, 1], so \(\cos^{-1}7x\) is defined when
\(-1 \le 7x \le 1\)
\( \displaystyle -\frac{1}{7} \le x \le \frac{1}{7} \)