Question

Найдите tg a, если sin a= 24/25

Answer 1

Tg a = sin a/cos a
cos^2 a = 1 - sin^2 a
cos^2 a = 1 - (24/25)^2
cos^2 a = 1 - (576 / 625)
cos^2 a = 49/625
cos a = 7/25   или   cos a = -7/25 
tg a = 24/25  : 7/25 = 24*25/25*7 = 24/7  
tg a 24/25  :(-7/25)  = -24/7