28A. ctg x =$$\frac{\sqrt{3}}{3}$$
29A. ctg x = $$\sqrt{3}$$
30A. ctg x = $$\frac{1}{\sqrt{3}}$$
31A. tg x = -$$\frac{\sqrt{3}}{3}$$
32A. tg x = -$$\sqrt{3}$$
33A. tg x = -$$\frac{1}{\sqrt{3}}$$
34A. ctg x = -$$\frac{\sqrt{3}}{3}$$
35A. ctg x = -$$\sqrt{3}$$
36A. ctg x = -$$\frac{1}{\sqrt{3}}$$