How to use it
- Type the number (decimals and negatives work).
- Pick the root: square, cube or up to the 10th.
- Read the decimal result, the simplified radical and the check.
Questions and answers
How do you simplify a square root?
Split the number into a perfect square times what is left and take the square root of the perfect square: √72 = √(36 × 2) = 6√2.
Can you take the square root of a negative number?
Not among real numbers. In complex numbers √−16 = 4i, where i is the imaginary unit (i² = −1). Odd roots of negatives are fine: ∛−27 = −3.
How do I estimate a square root by hand?
Find the two perfect squares around it: 50 is between 49 (7²) and 64 (8²), so √50 is a little more than 7 (it is about 7.07).