1003085605

Level: 
Project ID: 
1003085605
Accepted: 
1
Clonable: 
0
Easy: 
0
Find the set of all \( x\in\mathbb{R} \) for which \( \cos\!\left(\frac{\pi}4 - x\right) = 1 \).
\( \left\{\frac{\pi}4 + 2k\pi\colon k\in\mathbb{Z} \right\} \)
\( \left\{\frac{\pi}2 + 2k\pi\colon k\in\mathbb{Z} \right\} \)
\( \left\{\frac{\pi}4 + k\pi\colon k\in\mathbb{Z} \right\} \)
\( \left\{\frac{\pi}2 + k\pi\colon k\in\mathbb{Z} \right\} \)