Question

Пусть $sin x =3/5$, $x$∈$[ pi /2;3 pi /2]$. Найдите $tg x$

Answer 1

$cosx=sqrt{1-frac{9}{25}}=+-frac{4}{5}\\ cosx=-frac{4}{5}\\ x in [-frac{pi}{2};frac{3pi}{2}]\\ tgx=frac{frac{3}{5}}{-frac{4}{5}}=-frac{3}{4}$