After proving that:

$\displaystyle

tan(3x) = \frac{3tanx - tan^3(x)}{1-3tan^2(x)}

$

...how would i go aboutHENCEsolving:

$\displaystyle

1 - 3t^2 = 3t - t^3

$

Even just a nudge in the right direction would be of much help - I can see a link but just can't bring the two together!