🎲 Fun & Lifestyle
Square Root Calculator
√x — principal square root.
Enter values to see your result
Frequently asked questions
Why two roots: ±?
Both 3 and −3 square to 9. "√9 = 3" refers to principal (positive) root by convention. x² = 9 has two solutions: ±3.
Square roots of negatives?
Not in real numbers. Require imaginary: √−1 = i. √−4 = 2i.
Perfect squares?
Numbers whose square root is an integer: 1, 4, 9, 16, 25, 36, 49, 64, 81, 100, 121, 144, 169, 196...
Babylonian method?
Ancient iterative method: x_{n+1} = (x_n + a/x_n) / 2. Converges quadratically. Modern computers use similar (Newton's method).