Question

\( \cos^{-1}\left(\cos\left(\frac{7\pi}{5}\right)\right) = \)

• A. \( \frac{3\pi}{5} \)
• B. \( \frac{2\pi}{5} \)
• C. \( \frac{-7\pi}{5} \)
• D. \( \frac{7\pi}{5} \)
• E. \( \frac{-2\pi}{5} \)

Hint:

For \( \cos^{-1}(\cos \theta) \), if \( \theta \) is in the 3rd or 4th quadrant, use the formula \( 2\pi - \theta \) to bring it back to the principal range.

Answer 1

The Correct Option is A