Sin α=-7/25 и π<α<3π/2 найдите значения остальных тригонометрических функций

Решите задачу:

$sin \alpha =-7/25\\ \pi \ \textless \ \alpha \ \textless \ 3 \pi /2\\\\cos \alpha =б \sqrt{1-sin^2 \alpha }=б \sqrt{1-(-7/25)^2}=б \sqrt{1-49/625}=\\=б \sqrt{576/625}=б24/25\\\pi \ \textless \ \alpha \ \textless \ 3 \pi /2 =\ \textgreater \ cos \alpha =-24/25\\\\tg \alpha = \frac{sin \alpha }{cos \alpha }= \frac{-7/25}{-24/25}=7/24\\\\ctg \alpha = \frac{1}{tg \alpha }= \frac{1}{7/24}=24/7$