How do you find the cubed root of a number?

Question

E.G. The cubed root of 27 is 3. The cubed root of 8 is 2. How do they get that?

Answer 1

This seems to be a question of "how to" compute a number.

((ps it's called a "cube-root", not a 'cubed root' ... this just makes it easier for other people to understand))

There are two "easy" ways:
a) calculator
b) logarithms

/*******************************************/
a) by calculator [here using the
"Windows-scientific" calculator avail on 90%
of ordinary puters]

If you have a calculator, press in "27" and then press the "x^y" button and enter ".3333" .. if you use the calculator present on most computer with windows, it will display "2.99967..."

this is about equal to "3".

On a piece of paper you would write:

[ 27^(1/3) = 3 ] and say
"the cube root of 27 is 3"


To check, after pressing "C" [for "clear"], take the reverse operation of raining 3 to the 3rd power.

enter "3"
press "x^y"
enter "3"
.... read "27"

[ on a piece of paper you would write
3^3 = 27 ]

and say "three cubed is 27"

this means that "3 cubed = 27" which is the inverse operation of "taking the cube root"
/*******************************************/
b) logarithms [old-fashioned way]

to take the cube root of 1728, first find the
logarithm of 1728 [I'll use "common-log" here
which is base-10, tho ANY base wil work]

log (1728) = 3.3275 ...
divide this number by 3
3.3275 .../ 3 = 1.079 ...
take the anti-log of 1.079 ... [ie: find 10^1.079]
10^ 1.079... = 12

note: 12 * 12 * 12 = 1728 since 12 is the cube root of 1728

Answer 2

The only way you can do it each time is on your calculator. For scientific and graphing calculators, type in the number you want the cubed root of, then press the "^" button, and then press "(1/3)". The cubed root of a number is the same as that number raised to the 1/3 power (the same way the square root of a number is that number raised to the 1/2 power). Try typing in "27^(1/3)" and see what you get. Good luck!

Answer 3

Cubed root of 27 is 3---Why?
3x3x3=27 3x3=9x3=27
3x3x3=3^3 or 3 cubed

2x2x2=2^3 or 2 cubed 2x2=4x2=8

Answer 4

Factoring:
³\/27 =
27|3
09|3
03|3
01
³\/27 = ³\/3³ = 3
----
³\/8 =
8|2
4|2
2|2
1
³\/8 = 2*2*2 =
Cancelling the exponents, and ³\/2³ = ³\/8 = 2
<><

Answer 5

http://mathforum.org/library/drmath/view/52605.html