Question

pff me ajuda


matemática ​

Answer 1

$T = -1 + 2.cos[ \pi.\frac{t+1}{6}] \\ \\ -1 + 2.cos[ \pi.\frac{t+1}{6}] < 0  \\ \\  2.cos[ \pi.\frac{t+1}{6}] < 1  \\ \\ cos[ \pi.\frac{t+1}{6}] < \frac{1}{2} \\ \\ \frac{\pi}{3} < \pi.\frac{t+1}{6} < \frac{5\pi}{3} \\ \\ \frac{1}{3} < \frac{t+1}{6} < \frac{5}{3} \\ \\ 2 < t + 1 < 10 \\ 1 < t < 9$

letra a)