Son a =0.6 найти cost a tg a ctga если пи\2
Sin a = 3/5 Cos^2 a= 1-sin^2 a = 1-9/25= 16/25 Cos a=4/5 Tg^2 a+ 1 = 1/cos^2 a Tg^2 a= 25/16-1 Tg^2 a= 9/16 Tg a= 3/4 Ctg a= 4/3