Use an Addition or Subtraction Formula to Write $\frac { \tan \frac { 2 \pi } { 15 } + \tan \frac { 6 \pi } { 5 } } { 1 - \tan \frac { 2 \pi } { 15 } \tan \frac { 6 \pi } { 5 } }$

Essay

Use an addition or subtraction formula to write $\frac { \tan \frac { 2 \pi } { 15 } + \tan \frac { 6 \pi } { 5 } } { 1 - \tan \frac { 2 \pi } { 15 } \tan \frac { 6 \pi } { 5 } }$ and find the exact value.