Тригонометрия

 

sin x = a/c

cos x = b/c

tg x = a/b=sinx/cos x

ctg x = b/a = cos x/sin x

sin (-) = sin

sin (/2 -) = cos

cos (/2 -) = sin

cos ( + 2k) = cos

sin ( + 2k) = sin

tg ( + k) = tg

ctg ( + k) = ctg

sin + cos =1

tg = cos / sin, n, nZ

tg ctg = 1, (n)/2, nZ

1+tg = 1/cos , (2n+1)/2

1+ ctg =1/sin, n