Ответ:

sin^2+cos^2=1

cos^2=1-(√2/3)^2

cos^2=1-(2/9)

cos^2=7/9

cos=√7/3

tg=sin/cos

tg=√2/3/√7/3

tg=√(2/7)

ctg=1/tg=√(7/2)