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What positive number is the square root of half itself?

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Richard Walker

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Does this generalise?

Photo: Marco

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We are not talking whole numbers here, eh?

Daniel

Richard Walker

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That's right. It doesn't have to be an integer.

SXR103 chemistry is fun (2008) :-)

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0.5

Richard Walker

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Yes!

Could you give an explanation Jan? Obviously I could but yours might be better.

SXR103 chemistry is fun (2008) :-)

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I translated the written statement to algebra as 

x = √ (x/2)

then worked it through from there

x2 = x/2

2 x2 = x

2 = x / (x2)

2 = 1/x

x = 1/2

 x = 0.5

It may be a bit long winded, but I always have to plod through without many shortcuts.

Richard Walker

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Thanks Jan, that's a clear way to think of it.

The only thing I would add is that 0 seems to fit the bill, if you try it, but it's ruled out because we are told the number is positive, i.e. > 0.

Square root is power 1/2, so we have

1/2 = (1/2 of 1/2)1/2

which seems quite neat!

We also have

1/3 = (1/3 of 1/3 of 1/3)1/3

and so on.

SXR103 chemistry is fun (2008) :-)

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This could be why I'm registered to do MST124 from October.  I don't know all the possible little maths wrinkles yet smile

Jan