Cube root (∛x)
Calculate the cube root of a number, including negatives.
Graf funkce
Co je cube root
The cube root ∛x is the inverse of cubing – it finds the number which, when cubed, gives x. For example ∛27 = 3, because 3³ = 27.
Where it is used in practice
- Finding the edge of a cube from its volume.
- Scaling – from a ratio of volumes find the ratio of dimensions.
- Physics and chemistry when working with volumetric quantities.
Good to know
The cube root also works for negative numbers: ∛(−8) = −2, because (−2)³ = −8.
Rules of exponents
When working with powers it helps to know the basic rules, which always hold:
xⁿ · xᵖ = xⁿ⁺ᵖ (product – add the exponents)
xⁿ ÷ xᵖ = xⁿ⁻ᵖ (quotient – subtract the exponents)
(xⁿ)ᵖ = xⁿ·ᵖ (power of a power – multiply)
x⁻ⁿ = 1 / xⁿ (negative exponent)
x^(1/n) = ⁿ√x (root as a power)
In detail with examples: rules of exponents.
Tip: very large numbers are shown in shortened form – use scientific notation.