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Simplified form of √72
62
≈ 8.485281
Coefficient (a) 6
Radicand (b) 2
Decimal value 8.485281

What this calculator does

The Simplifying Radicals Calculator rewrites a square root \(\sqrt{n}\) into its simplest radical form \(a\sqrt{b}\). It extracts the largest perfect-square factor of n so the number left under the radical is as small as possible. This is a core skill in algebra, geometry, and trigonometry where exact answers are preferred over decimal approximations.

How to use it

Type any positive whole number into the field and submit. The calculator finds the largest integer a whose square divides n, then reports the coefficient a, the remaining radicand b, the full simplified form \(a\sqrt{b}\), and the decimal approximation. If n is already a perfect square, the result is just an integer; if n has no square factors greater than 1, the radical is already in simplest form.

The formula explained

We write $$\sqrt{n} = a\sqrt{b} \qquad a^2 \cdot b = n$$ where \(a^2\) is the largest perfect square that divides n and \(b = n / a^2\). For example, \(72 = 36 \times 2\), and \(36 = 6^2\) is the largest perfect square factor, so \(\sqrt{72} = 6\sqrt{2}\). The factor 6 comes out of the radical and 2 stays inside because 2 has no perfect-square factors.

Diagram showing a square root broken into a perfect square factor and a remaining factor
Splitting the radicand into a perfect square times the remaining factor gives the simplified form \(a\sqrt{b}\).

Worked example

Simplify \(\sqrt{72}\). List perfect-square divisors of 72: 1, 4, 9, 36. The largest is \(36 = 6^2\). So \(a = 6\) and \(b = 72 / 36 = 2\). Therefore $$\sqrt{72} = 6\sqrt{2} \approx 8.485281$$

Worked example showing square root of 72 simplified to 6 times square root of 2
Example: \(\sqrt{72} = \sqrt{36 \cdot 2} = 6\sqrt{2}\).

FAQ

What if my number is a perfect square? Then \(b = 1\) and the answer is the whole number a — for example \(\sqrt{49} = 7\).

Can it handle numbers that are already simplest? Yes. \(\sqrt{15}\) has no square factor besides 1, so it returns \(1\sqrt{15}\), displayed as \(\sqrt{15}\).

Does it work with non-square-free results like \(\sqrt{48}\)? Yes: \(48 = 16 \times 3\), so \(\sqrt{48} = 4\sqrt{3} \approx 6.928203\).

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