Can anyone explain the following:

A)

and the ratio/proportion:

B)

: = :

thanks in advance

How on earth is A) true?

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- Sep 27th 2009, 09:58 AMportiaroot question
Can anyone explain the following:

A)

and the ratio/proportion:

B)

: = :

thanks in advance

How on earth is A) true? - Sep 27th 2009, 10:03 AMMacstersUndead
A) You can rewrite this equation with exponents

Consider that the square root of 2 = 2^(1/2)

now with the exponent law of division, can you finish? - Sep 27th 2009, 10:14 AMe^(i*pi)

And as we know multiplying by 1 does not affect the value of a number.

You'll come across this more when it comes to*Rationalising the Denominator* - Sep 27th 2009, 10:24 AMGrandad
Hello portiaThe only things you really need to understand here are:

- (because that's what a square root is)

- how to 'cancel' a fraction

Then it works like this:

... and 'cancel' in the usual way:

For B, you also need to understand that ratios work exactly like fractions: you can 'cancel' (i.e. divide each number in the ratio by the same thing) or you can 'un-cancel' (if there is such a word) by*multiplying*each number in the ratio by the same thing.

So starting with , multiply each number by :

Grandad - (because that's what a square root is)
- Sep 27th 2009, 10:25 AMportia
Thanks, I understand it now. After substracting the exponents we're left with 2^(-1/2) which gives 1 over the square root of 2.

My maths skills are VERY rusty.

What about the ration question?

edit: sorry, I only saw the first reply. - Sep 27th 2009, 11:36 AMportia
Thanks guys, I get it now