Revision as of 14:39, 3 December 2008 by Bpitstic (Talk)

Following the same procedures as with a square root does not get me anywhere. Does anyone have any suggetions? on how to find the minimal polynomial for a cube root?! --Robertsr 23:49, 2 December 2008 (UTC)

Yea, I keep trying to solve this in a similar way as 14 but it doesn't work. Grrr.

Remember that $ \sqrt[3]{4}=(\sqrt[3]{2})^2 $ so $ \sqrt[3]{4} $ is the only important one

--

As stated above: $ \sqrt[3]{4}=(\sqrt[3]{2})^2 $, so [Q($ \sqrt[3]{2}+sqrt[3]{4} $:Q]=3. This means we need a polynomial of degree 3. You can use the same process as 14 by letting x=$ \sqrt[3]{2}+sqrt[3]{4} $ then find $ \x^3 $ which I found to equal 6x-6. (I found it easier to refer to $ \sqrt[3]{2}+sqrt[3]{4} $ as $ \2^(1/3) $ and $ \2^(2/3) $ when doing the calculations.) I think this is right as the polynomial has $ \sqrt[3]{2}+sqrt[3]{4} $ as a zero. Did anyone else get this?

Alumni Liaison

Ph.D. 2007, working on developing cool imaging technologies for digital cameras, camera phones, and video surveillance cameras.

Buyue Zhang