### Instruction: If $\tan \theta = 4,$ then find $\tan 3 \theta.$.### Response: I know that $\tan 3 \theta$ can be expressed as $\frac{3 \tan \theta - \tan^3 \theta}{1 - 3 \tan^2 \theta}$ by using the triple angle formula for tangent.
So I can plug in $\tan \theta = 4$ and simplify.