Math Is Fun Forum

sologuitar

Member

Registered: 2022-09-19

Posts: 467

Rationalize Denominator

Rationalize Denominator

Let cb = cube root

5/[cr{2}]

I multiplied the top and bottom by [cr{2}].

After doing that I ended up with (5•cr{2})/2 as my final answer.

The book's answer is (5•cr{4})/2.

Where did 4 come from?

Bob

Administrator

Registered: 2010-06-20

Posts: 10,196

Re: Rationalize Denominator

It's a cube root not a square root.

To turn the denominator into a rational number you need to multiply by the cube root squared.

Bob

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Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob

sologuitar

Member

Registered: 2022-09-19

Posts: 467

Re: Rationalize Denominator

It's a cube root not a square root.

To turn the denominator into a rational number you need to multiply by the cube root squared.

Bob

Wow! How on earth did I miss that? Thanks.