icus ' ▁De ▁revolution ibus ▁orb ium ▁co el est ium ▁and ▁V es al ius ' ▁De ▁hum ani ▁corpor is ▁fab rica . ▁The ▁first ▁ed itions ▁of ▁these ▁three ▁books ▁were ▁published ▁within ▁a ▁two - year ▁span ▁( 1 5 4 3 – 1 5 4 5 ). ▁ ▁History ▁In ▁ 1 5 3 5 ▁Nic col ò ▁Font ana ▁T art aglia ▁became ▁famous ▁for ▁having ▁solved ▁cub ics ▁of ▁the ▁form ▁x 3   +   ax   =   b ▁( with ▁a , b   >   0 ). ▁However , ▁he ▁chose ▁to ▁keep ▁his ▁method ▁secret . ▁In ▁ 1 5 3 9 , ▁Card ano , ▁then ▁a ▁lect urer ▁in ▁mathematics ▁at ▁the ▁Pi atti ▁Foundation ▁in ▁Milan , ▁published ▁his ▁first ▁mathematical ▁book , ▁Pr atica ▁Ar ithmetic æ ▁et ▁mens ur and i ▁singular is ▁( The ▁Pract ice ▁of ▁Ar ithmetic ▁and ▁Simple ▁Mens uration ). ▁That ▁same ▁year , ▁he ▁asked ▁T art aglia ▁to ▁explain ▁to ▁him ▁his ▁method ▁for ▁solving ▁cub ic ▁equations . ▁After ▁some ▁rel uct ance , ▁T art aglia ▁did ▁so , ▁but ▁he ▁asked ▁Card ano ▁not ▁to ▁share ▁the ▁information ▁until ▁he ▁published ▁it . ▁Card ano ▁sub mer ged ▁himself ▁in ▁mathematics ▁during ▁the ▁next ▁several ▁years ▁working ▁on ▁how ▁to ▁extend ▁T art aglia ' s ▁formula ▁to ▁other ▁types ▁of ▁cub ics . ▁Furthermore , ▁his ▁student ▁L od ov ico ▁Ferr ari ▁found ▁a