How do you rationalize the denominator and simplify 3/sqrt12?

2 Answers
Mar 20, 2016

= sqrt12/4

Explanation:

3 / sqrt12

(3 * color(blue)(sqrt12))/(( sqrt12 * color(blue)( sqrt12))

= ((3sqrt12))/12

= (cancel3sqrt12)/cancel12

= sqrt12/4

Mar 20, 2016

Bit more explanation

= (sqrt(12))/4

Explanation:

If you multiply a value by 1 you do not change its intrinsic value.

The thing is, 1 can come in many forms. For example" " 3/3.

So you can write 1 as 1=sqrt(12)/sqrt(12)

Given:" "3/sqrt(12)

Multiply by 1 but in the form 1=sqrt(12)/sqrt(12)

" "3/sqrt(12)xxsqrt(12)/(sqrt(12))

=(3xxsqrt(12))/(sqrt(12)xxsqrt(12))

=(3sqrt(12))/12

Divide top and bottom by 3

=(3sqrt(12)-:3)/(12-:3)

=(sqrt(12))/4

'~~~~~~~~~~~~~~~~~~~~~~~~~~~~
color(red)("If you really wanted to be absolutely correct about the answer ")
color(red)("consider this:")

sqrt(12) is a number that when multiplied by itself results in +12

However sqrt(12) could be negative. Think about:

(-3)xx(-3) = +9 = (+3)xx(+3)

So should the answer be:

color(green)(+-sqrt(12)/4)

color(red)("No!")

The question gives: (sqrt(12))/4

The absence of any sign means that it is positive. Consequently the questions single sqrt(12) is positive. So the solutions single sqrt(12) has to be positive as well.