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**richard clark****Member**- Registered: 2009-05-28
- Posts: 1

I need to transpose a formula and my algebra isn't up to it. I would welcome any suggestions or solutions. the formula is:

S = (A * (A + 1) * (A + 2))

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6

I need to rearrange this and make "A" the subject of the formula. I believe there is a method using sucessive approximations but I would prefer not to take this approacg. If anybody fancies a little bit of brain-bashing, please feel free.

Many thanks

Richard Clark

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**Ricky****Moderator**- Registered: 2005-12-04
- Posts: 3,791

Algebra won't be enough. You have the points A = 0, A = -1, and A = -2 all give the value S = 0. This means the inverse (i.e. solving for A) won't be a function. You can locally come up with approximations for the inverse where the derivative with respect to A is nonzero, but this is about all you can do.

"In the real world, this would be a problem. But in mathematics, we can just define a place where this problem doesn't exist. So we'll go ahead and do that now..."

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