Теңсіздікті шешіңіз: 0 < cosx ≤ 1/(√2)

Жауап нұсқалары

1. A.$\left( -\frac{\pi}{2} + 2\pi n,\; -\frac{\pi}{4} + 2\pi n \right) \cup \left( \frac{\pi}{4} + 2\pi k,\; \frac{\pi}{2} + 2\pi k \right), \quad n,k \in \mathbb{Z}$
2. B.$\left( -\frac{\pi}{2} + 2\pi n,\; -\frac{\pi}{4} + 2\pi n \right) \cup \left[ \frac{\pi}{4} + 2\pi k,\; \frac{\pi}{2} + 2\pi k \right], \quad n,k \in \mathbb{Z}$
3. C.$\left( -\frac{\pi}{2} + 2\pi n,\; \frac{\pi}{4} + 2\pi n \right) \cup \left[ -\frac{\pi}{4} + 2\pi n,\; \frac{\pi}{2} + 2\pi n \right], \quad n \in \mathbb{Z}$
4. D.$\left( -\frac{\pi}{2} + 2\pi n,\; -\frac{\pi}{4} + 2\pi n \right) \cup \left[ \frac{\pi}{4} + 2\pi n,\; \frac{\pi}{2} + 2\pi n \right], \quad n \in \mathbb{Z}$дұрыс