Найти sin,tg ,ctg если cos 5/13 и 3П/2<а<2П

Question

Найти sin,tg ,ctg если cos 5/13 и 3П/2<а<2П

Answer 1

Cosx = 5/13
Sinx = √1 - Cos^2x = 1 - 25/169 = √144/169 = 12/13
tgx = Sinx/Cosx = 12/13 * 13/5 = 12/5 
ctgx = Cosx/Sinx = 5/13 * 13/12 = 5/12