Find the nth root of any number.
Enter a value and a root degree to see its nth root, its square and cube roots, and a check that the result raised back to the power n returns your original number.
Your numbers
What this means
Roots of your number
| Root | Notation | Result | Check (result ^ n) |
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Understanding roots
Understanding Roots
The nth root of a number x is a value that, when raised to the power n, gives x. The square root (2nd root) of 9 is 3 because 3² = 9. The cube root (3rd root) of 27 is 3 because 3³ = 27. Mathematically, ⁿ√x = x^(1/n).
Square Roots and Perfect Squares
A perfect square is a number whose square root is an integer: 1, 4, 9, 16, 25, 36, 49, 64, 81, 100, etc. Non-perfect squares have irrational square roots (e.g., √2 ≈ 1.4142). The square root function is essential in geometry (Pythagorean theorem), physics, and statistics.
Cube Roots and Higher Roots
Cube roots can handle negative numbers (∛(-8) = -2). Fourth roots behave like square roots (no real result for negatives). In general, odd roots exist for all real numbers, while even roots require non-negative inputs for real results.
Applications of Roots
Square roots appear in the Pythagorean theorem, distance formula, and standard deviation. Cube roots arise in volume calculations (finding edge length from volume). Higher roots are used in financial calculations (geometric mean return) and engineering formulas.
Common questions
Can you take the square root of a negative number?
Not in real numbers, the result is an imaginary number (e.g., √(-1) = i). Cube roots and other odd-degree roots of negative numbers do have real results (e.g., ∛(-8) = -2).
What is the difference between √ and ^(1/2)?
They are the same operation. The radical symbol √x is equivalent to x^(1/2). Similarly, ∛x = x^(1/3), and the nth root ⁿ√x = x^(1/n).
Is √2 rational or irrational?
√2 is irrational, it cannot be expressed as a fraction of two integers. Its decimal expansion (1.41421356...) goes on forever without repeating. This was proven by the ancient Greeks.
How accurate is this calculator?
This calculator uses JavaScript floating-point arithmetic, which provides approximately 15-17 significant digits of precision. For most practical purposes, this is more than sufficient.
Results use floating-point arithmetic (about 15 to 17 significant digits). Irrational roots are shown rounded.