What is the square root of 15?

The square root of 15 is one of those numbers that doesn't have a clean, whole answer. It's an irrational number, which just means the decimal goes on forever without a repeating pattern.

For any practical purpose, like for a math problem, you'll want a rounded decimal. The answer is approximately 3.873.

A good way to check this is to remember that 3x3 is 9 and 4x4 is 16. So, the square root of 15 has to be a number between 3 and 4, but a lot closer to 4.

The square root of 15 is an irrational number, approximately equal to 3.872983346. It cannot be expressed as a simple fraction, but it lies between 3 and 4. Mathematically, √15 × √15 = 15.

If you want the value for practical purposes, you can approximate √15 ≈ 3.87. This is often enough for calculations in physics or engineering. If you need more precision, you can use a calculator or compute it using Newton’s method.

From a mathematical perspective, 15 is not a perfect square, which means its square root cannot be simplified into a whole number. However, you can simplify √15 in algebraic expressions (like √(3×5) = √3 × √5).

Fun fact: The square root of 15 often appears in trigonometry and geometry problems. For example, when dealing with Pythagoras theorem in right-angled triangles, √15 might come up as the length of one side.