.
Solve the given equation. 
   3tan^3(x)=tan(x)
~~~~~~~~~~~~~~~~~~~~~~~
This equation comes apart in two equations:
1.  tan(x) = 0  with solutions  x =  ,  k = 0, +/-1, +/-2, . . . 
    and
2.
,  k = 0, +/-1, +/-2, . . . 
    and
2.   =
 =  --->  tan(x) = +/-
  --->  tan(x) = +/-  with solutions   x = +/-
  with solutions   x = +/-  +
 +  ,  k = 0, +/-1, +/-2, . . .
,  k = 0, +/-1, +/-2, . . .