show that one fo the roots of the equation is and find the other two roots

Printable View

- October 15th 2008, 04:26 PMsiegfriedcubic equation help
show that one fo the roots of the equation is and find the other two roots

- October 15th 2008, 08:04 PMThePerfectHacker
- October 15th 2008, 09:24 PMsiegfried
thank you theperfecthacker

i believe you are using cardanos method but i think there is an easier method than cardanos - October 15th 2008, 09:30 PMThePerfectHacker
- October 16th 2008, 04:07 AMOpalg
Use the formulas and . These show that if then , and so . But if then . That gives the equation . The other two solutions will come from the other angles satisfying , namely and . (

**ThePerfectHacker**had , but I think must be correct.) - October 16th 2008, 08:25 AMThePerfectHacker