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# Gauss Jordan or Cofactor? Watch

1. Hi everyone

Just a quick question... do you (generally) think it's quicker to use Gauss Jordan Elimination or the cofactor method to find the inverse of a 3x3 matrix?

(using pen and paper)
2. Personally, I'm quicker doing cofactors but I think for a 3x3 the difference is probably negligible.
3. I'd probably do Gaussian elimination even though it's slower — I don't trust myself to remember the cofactor formula!
4. (Original post by Zhen Lin)
I'd probably do Gaussian elimination even though it's slower — I don't trust myself to remember the cofactor formula!
I think they made us do it for A-level. (I can't see any other reason why I would have learnt it)
5. Can't wait to do the further pure units. This is FP3 isn't it?
6. I learned both at A-level but in the first semester of uni we've only been doing the gauss-jordan elimination. It allows you to write down the elementary matrices and elementary inverses as you do it. I find it faster tbh.
7. (Original post by MostCompetitive)
Can't wait to do the further pure units. This is FP3 isn't it?
Inverting matrices is not exciting.

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Updated: December 25, 2010
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