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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 bundy
Registered: 2010-06-20
Posts: 8,321

### 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

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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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