Question

tgx=0.2 чему равно x

Answer 1

tgx=1/5
x=arctg1/5+πn, n∈Z.

Answer 2

$tgx=0.2 \ tgx= frac{2}{10} = frac{1}{5} \ \ x=arctg frac{1}{5} + pi n$
n∈Z