The trigonometric equation is
.
Subtract
from each side.

Add
to each side.

Since the period of the tangent function is
, the only solution on the interval is
.
Solve
.
or 
or 
The general solution of
is
, where
is an integer.
The general solutions are
or
, where
is an integer.
The solutions are
or
, where
is an integer.