5. ctg t=0

5. ctg t = 0

Решение:

$$ctg \; t = 0$$

$$t = arcctg \; 0 + \pi n, n \in Z$$

$$t = \frac{\pi}{2} + \pi n, n \in Z$$

Ответ: $$t = \frac{\pi}{2} + \pi n, n \in Z$$