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#1 2012-10-19 19:49:48

Harold
Guest

Cubic equation

How do i solve a equation of this form ax^3+bx^2+cx+d=0 is there a formula?please explain

#2 2012-10-19 20:34:50

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Cubic equation

Hi Harold;

Yes, there is a formula but no one ever uses it.


In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

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#3 2012-10-19 20:45:15

zetafunc.
Guest

Re: Cubic equation

It would be helpful to remember but you're unlikely to use it very often. Try to find the first by inspection (or iteration if you have a calculator), then determine the quadratic factor from there.

#4 2012-10-19 20:53:55

Bob
Administrator
Registered: 2010-06-20
Posts: 10,052

Re: Cubic equation


Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob smile

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#5 2012-10-20 08:32:14

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Cubic equation

Or one even nastier than that.

http://www.mathisfunforum.com/viewtopic … 00#p198900

See post#6.


In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

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