#### Monkeyseat

##### Full Member

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- Thread starter Monkeyseat
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- Joined
- Jul 3, 2005

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Let's substitute our solution into the equation to check:

\(\displaystyle A = \sqrt{3 \frac{A^2}{3}\ }\ = \sqrt{A^2}\\)

This is only true for non-negative A.

So, let's revise the solution:

\(\displaystyle P = \frac{A^2}{3}\\), for non-negative A.

- Joined
- Jul 3, 2005

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Sorry, so which solution was correct? Is the answer from the book incorrect?

Thanks.

Thanks.

- Joined
- Jul 3, 2005

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It wasn't really a book, it was the mark scheme for a GCSE test so I didn't think it would be wrong but I couldn't find how they got that answer...

Thanks for the help.