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1. Cubed roots
Hi,
I'm stuck on an equation. x^3=16000 * sqrt 2. This apparently can be reduced down to x = 20 * sqrt 2. I don't know how to do this, can anyone give me any help. Is it possible to cube root a square? I can find the answer 28.28 when using a calculator but would like to actually understand it. Many thanks.
2. Re: Cubed roots
(Original post by jrowe)
Hi,
I'm stuck on an equation. x^3=16000 * sqrt 2. This apparently can be reduced down to x = 20 * sqrt 2. I don't know how to do this, can anyone give me any help. Is it possible to cube root a square? I can find the answer 28.28 when using a calculator but would like to actually understand it. Many thanks.
Your best bet is to convert it all to indices.

First notice that and , so . And , so by the laws of indices we have

Now take the cube root of both sides, using the laws of indices to simplify the RHS, and you'll see that it simplifies to give the above answer.
3. Re: Cubed roots

Can you do it now?
4. Re: Cubed roots
OK, so then
X^3= 20^3 * sqrt2 ^3
And then just get rid of all the ^3,
If that's right then thank you!!!
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