# Math Help - rationalise

1. ## rationalise

i need to rationalise the denominators of this $\frac{1}{\sqrt{3}}$

can someone explain what i need to do?

2. Multiply by $\frac{\sqrt{3}}{\sqrt{3}}$ to change the denominator to an integer.

3. Originally Posted by Archie Meade
Multiply by $\frac{\sqrt{3}}{\sqrt{3}}$ to change the denominator to an integer.

i was gonna post because i thought it was that, so the answer would be

4. yes, but do you need the 1?

5. Yes, that's it,

beyond that,
you would use the "surd conjugate" when the denominator is
composed of an integer and square root....

example

$\frac{1}{2+\sqrt{3}}=\frac{1}{2+\sqrt{3}}\ \frac{2-\sqrt{3}}{2-\sqrt{3}}$

6. Originally Posted by VonNemo19
yes, but do you need the 1?

no!!!

7. understand that rationalise the denominator means to change the denominator so that it is a rational number (i.e. no surds!)

some people rote learn maths and decide to multiply top and bottom by the denominator, which is obviously not the case, as sometimes you need to multiply by the surd conjugate.
so yeah