In my university level history of mathematics course I have encountered the following problem, I have to admit I am stuck!

Solve the following cubic function using Cardanos method: x^{3}+ 3x = 2

(Cardano, Ars magna, Caput XI, De Cubo & rebus aequalibus Numero.)

Also calculate an approximation with three decimals (using the method)

Any help would be much appreciated!