The domain of $f(x)=\cos^{-1}7x$ is:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → $\left[-\frac{1}{7},\frac{1}{7}\right]$
Domain of $f(x)=\cos^{-1}x$ is $[-1,1]$
∴ Domain of $\cos^{-1}7x$ = $\left[-\frac{1}{7},\frac{1}{7}\right]$