hi, i need to rationalise the denominator of this, $\displaystyle \frac{1}{2\sqrt{3}} $

how would i work this out?

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- Jan 16th 2010, 02:26 AMandyboy179rationalising denominators
hi, i need to rationalise the denominator of this, $\displaystyle \frac{1}{2\sqrt{3}} $

how would i work this out? - Jan 16th 2010, 02:54 AMpickslides
Here's one I prepared earlier.

Consider

$\displaystyle \frac{1}{4\sqrt{5}} $

Let's times it by 1 because that won't change anything

$\displaystyle \frac{1}{4\sqrt{5}}\times 1 $

But 1 comes in many forms I.e $\displaystyle \frac{a}{a}=1, a\neq 0 $

So lets make it the following

$\displaystyle \frac{1}{4\sqrt{5}}\times \frac{\sqrt{5}}{\sqrt{5}} $

I did this because $\displaystyle \sqrt{a}\times \sqrt{a}= a$

Now we have

$\displaystyle \frac{1\times \sqrt{5}}{4\sqrt{5}\times \sqrt{5}} $

$\displaystyle \frac{\sqrt{5}}{4\times 5} $

We have no radical in the denominator so we are finished.

Apply this method to your problem. - Jan 16th 2010, 03:00 AMandyboy179
- Jan 16th 2010, 03:09 AMpickslides
- Jan 16th 2010, 03:13 AMandyboy179
would the answer to my question be, Attachment 14842 ?

- Jan 16th 2010, 03:23 AMpickslides
Yes, yes it is

(Clapping) - Jan 16th 2010, 03:26 AMandyboy179
thank you so much, you'd make a great teacher!!!

- Jan 16th 2010, 03:30 AMandyboy179
oh ye one others thing, is this right? Attachment 14844

- Jan 16th 2010, 03:34 AMmr fantastic