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## #1 2012-10-20 18:49:48

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 2012-10-20 19:34:50

bobbym

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### 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.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

## #3 2012-10-20 19:45:15

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 2012-10-20 19:53:55

bob bundy
Moderator

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### Re: Cubic equation

You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei

## #5 2012-10-21 07:32:14

bobbym

Offline

### 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.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.