hey all,

i got the following problem to solve:

i got this term: 27*g^2+4*p^3<0

and i need to proof that there are three real roots to this function:

x^3+px+q=0

is it enough to solve it by min/max points of the function?

Printable View

- February 13th 2010, 03:41 AMdanneeIntermediate value problem
hey all,

i got the following problem to solve:

i got this term: 27*g^2+4*p^3<0

and i need to proof that there are three real roots to this function:

x^3+px+q=0

is it enough to solve it by min/max points of the function? - February 13th 2010, 06:02 AMGrandadCondition for a cubic to have real roots
Hello danneeI'm sure you mean:

Every cubic has at least one real root, so let's assume that has a real root . Then:, for some constants and .Comparing coefficients:

Grandad - February 13th 2010, 06:27 AMdannee
i'm really really sorry, i wrote a bad syntax.... the right term should be:

and i need to prove that there are three real roots to this function:

thanks alot and sorry again - February 13th 2010, 08:14 AMCaptainBlack