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Root calculators

These root calculators provide three tools to compute roots of numbers. It includes a square root calculator, a cube root calculator, and a general root calculator where you can specify both the number and the root (e.g., 4th root or 5th root).

Square root calculator

Cube root calculator

General root calculator

Related calculators:


What is a root?

A root of a number is a value that, when raised to a specific power, equals the original number.

In general:

  • For a number x and a root n, the n-th root of x is a value r such that:
r^n = x

For example:

  • The square root of 16 (\sqrt{16}) is 4 because 4^2=16
  • The cube root of 27 (\sqrt[3]{27}) is 3 because 3^3=27

How can a root be found in general?

To find the n-th root of a number x, you use the formula:

r = x^{\frac{1}{n}}
  • Here, \frac{1}{n}​ is the reciprocal of n.
  • This formula works for any positive number xxx and positive integer n.

In programming, most modern languages, including JavaScript, use the Math.pow(x, 1/n) or x ** (1/n) methods for general root calculation.

How can a square root be found?

The square root of a number x is a value r such that:

r^2 = x
  • Formulaically, it is:
r = x^{\frac{1}{2}} \quad \text{or} \quad \sqrt{x}

Example: \sqrt{9}=3 because 3^2=9

In practice, you can:

  1. Use the formula r=x^{0.5}.
  2. Use a calculator or programming library function like Math.sqrt(x) in JavaScript.

How can a cube root be found?

The cube root of a number x is a value r such that:

r^3 = x
  • Formulaically, it is:
r = x^{\frac{1}{3}} \quad \text{or} \quad \sqrt[3]{x}

Example: \sqrt[3]{8}=2 because 2^3=8

In practice, you can:

  1. Use the formula r=x^{\frac{1}{3}}.
  2. Use a calculator or programming library function like Math.cbrt(x) in JavaScript.

Summary table

Root typeFormulaExampleProgramming function
Square rootx^{\frac{1}{2}} \quad \text{or} \quad \sqrt{x}\sqrt{16}=4Math.sqrt(x)
Cube root
x^{\frac{1}{3}} \quad \text{or} \quad \sqrt[3]{x}
\sqrt[3]{27}=3Math.cbrt(x)
General rootx^{\frac{1}{n}}16^{\frac{1}{4}}=2Math.pow(x, 1/n) or x ** (1/n)