Question

вычистить ctg4альфа, если ctg2альфа=1/4.

Answer 1

sin a = 1/4
sin^2 a = 1/16
cos^2 a = 1 - 1/16 = 15/16
ctg^2 a = 15
ctg a = -√15

Answer 2

sin a = 1/4
sin^2 a = 1/16
cos^2 a = 1 - 1/16 = 15/16
ctg^2 a = 15
ctg a = -√15