Updated: 2026-04-07

Radical Simplifier Tool: Your Free Online Calculator for Nth Degree Roots

Overview: This article explains the fundamentals of radical notation and operations. A radical, denoted as ⁿ√x, represents the root of a number and is the inverse operation of exponentiation with a fractional exponent. We cover essential rules and practical guidance for adding, subtracting, multiplying, and dividing radicals.

What is a Radical in Mathematics?

In mathematical terms, a radical represents the root of a number. The formal definition is expressed by the equation:

r^n = x, which can be rewritten as r = x^(1/n).

Here, 'r' is the radical's result. Essentially, taking a radical is the inverse operation of exponentiation where the exponent is a fraction. The radical notation r = ⁿ√x provides a simplified way to express this relationship.

Essential Rules for Radical Notation

Calculating roots is subject to specific conditions. Generally, the radicand (the number under the radical sign) should be positive. An exception exists for odd-degree roots, like cube roots (n=3), where negative radicands are permissible. The root degree 'n' is typically a positive integer.

To summarize for the radical ⁿ√x:

  • n should be a positive integer.
  • x should be a non-negative real number.

Adding and Subtracting Radicals

Adding or subtracting radicals requires both the radical degree and the radicand to be identical.

For example:

✅ ⁴√7 + 2⁴√7 = 3⁴√7
✅ 5∛5 + 3∛5 = 8∛5

Sometimes, simplification makes addition possible. Consider ∛192 + ∛3. By simplifying ∛192 to ∛(64×3) = ∛64 × ∛3 = 4∛3, both terms now share the same radical form, allowing addition: 4∛3 + ∛3 = 5∛3. The rules for subtraction are identical.

Multiplying Radicals

When multiplying radicals of the same degree, you can multiply the radicands directly.

Example: ⁴√7 × ⁴√4 = ⁴√(7×4) = ⁴√28.

If coefficients exist outside the radical, multiply them separately: 4∛3 × 2∛5 = (4×2)∛(3×5) = 8∛15.

To multiply radicals with different degrees but the same radicand, convert to exponent form. For instance:

⁴√2 × ∛2 = 2^(1/4) × 2^(1/3) = 2^(1/4 + 1/3) = 2^(7/12) = ¹²√128.

Dividing Radicals

The rules for division mirror those for multiplication. For radicals with the same degree, divide the radicands.

Example: ⁵√8 / ⁵√4 = ⁵√(8/4) = ⁵√2.

With coefficients: 5∛15 / 2∛5 = (5/2)∛(15/5) = 2.5∛3.

For different degrees, use the exponent method. For ⁴√6 / ⁵√6, convert to 6^(1/4) / 6^(1/5) = 6^(1/4 - 1/5) = 6^(1/20) = ²⁰√6.

Radical Function and Graphs

The basic radical function is f(x) = ⁿ√x, where n is a positive integer. For n=2, this is the familiar square root function. The function can be generalized with parameters:

f(x) = a × ⁿ√(b×x - h) + k.
  • 'a' vertically scales the graph.
  • 'b' horizontally scales the graph.
  • 'h' shifts the graph horizontally.
  • 'k' shifts the graph vertically.

These parameters translate the basic radical graph, allowing for precise graphical modeling. Understanding the rules for radicands is key to defining the domain of these functions.

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