Once again, Greta is in a pickle! She is trying to solve the following equation and knows she can use $u$-substitution.

$3 \tan^2(x) - \tan(x) - 10 = 0$

1. Greta thinks if she lets $u = \tan(x)$ she can write the equation as a quadratic equation. Show Greta she is correct.

   Hint (a):

   $3u^2 − u − 10 = 0$
   Solve for $u$.
   Then solve for $x$.

2. Use your answer to part (a) to solve for $x$.

   Partial Answer (b):

   $x=\tan^{−1}(2)\approx1.107+\pi n$