√93 at a glance
- Exact value
- √93
- Decimal (10 places)
- 9.6436507610
- Rounded
- 9.6 · 9.64 · 9.644
- Perfect square?
- No — between 9² and 10²
- Rational?
- Irrational
- Both square roots
- ±9.643651
- Prime factorization
- 3 × 31
- Cube root
- 4.530655
How to simplify √93
The prime factorization of 93 is 3 × 31. Every prime appears only once, so there is no pair to bring outside the radical — √93 is already in simplest form (a "square-free" radicand).
A whole number has a rational square root only when every prime in its factorization appears an even number of times. In 93, 3 and 31 appear an odd number of times, so √93 is irrational and 9.6436507610 is a rounded value.
Where √93 sits between perfect squares
81 = 9² and 100 = 10² are the nearest perfect squares, so √93 lies between 9 and 10. 93 is 12 above 81 and 7 below 100, so the root is closer to 10.
- Straight line between 81 and 100: 9.6316 (0.13% low)
- Tangent from 9, i.e. 9 + 12 ÷ 18: 9.6667 (0.24% high)
- Tangent from 10, i.e. 10 − 7 ÷ 20: 9.6500 (0.07% high)
For √93 the tangent at 10 wins, missing by only 0.0063. Tangent estimates shine when the number sits close to a perfect square — here 93 is just 7 below 100.
Finding √93 with the Babylonian method
This is Newton’s method applied to f(x) = x² − 93: following the tangent line down to zero simplifies to averaging x with 93 ÷ x.
Start from the nearest whole number, 10 (10² = 100):
| Step | Guess x | 93 ÷ x | Average | Correct decimals |
|---|---|---|---|---|
| 1 | 10.0000000000 | 9.3000000000 | 9.6500000000 | 2 |
| 2 | 9.6500000000 | 9.6373056995 | 9.6436528497 | 5 |
| 3 | 9.6436528497 | 9.6436486722 | 9.6436507610 | all 10 shown |
The count of correct decimals went 2, 5 and all 10 over 3 steps — roughly doubling each time — until the guess matched √93 = 9.6436507610 to every decimal shown.
√93 as a continued fraction
Every irrational square root has a continued fraction that repeats. For √93 the pattern is [9; 1, 1, 1, 4, 6, 4, 1, 1, 1, 18] with the block of 10 terms after the semicolon repeating forever. A pattern that never ends is one more proof that √93 is irrational.
Cutting the continued fraction off early gives the best fractions for approximating the root — no fraction with a smaller denominator comes closer:
| Fraction | Decimal | Error |
|---|---|---|
| 9/1 | 9.0000000000 | 6.4 × 10⁻¹ |
| 10/1 | 10.0000000000 | 3.6 × 10⁻¹ |
| 19/2 | 9.5000000000 | 1.4 × 10⁻¹ |
| 29/3 | 9.6666666667 | 2.3 × 10⁻² |
| 135/14 | 9.6428571429 | 7.9 × 10⁻⁴ |
| 839/87 | 9.6436781609 | 2.7 × 10⁻⁵ |
The same fractions solve Pell’s equation, x² − 93y² = 1. Its smallest solution in positive whole numbers is x = 12,151, y = 1,260.
√93 in geometry and everyday measurements
- A square room or garden bed covering 93 square feet measures about 9.64 ft (9 ft 8 in) along each wall.
- 93 is not a sum of two whole-number squares — the prime factor 3 and 31 (one less than a multiple of 4) appears an odd number of times, which rules that out — so √93 is never the diagonal of a rectangle with whole-number sides. It is, however, the space diagonal of a 2 × 5 × 8 box, because 2² + 5² + 8² = 93.
Square roots near √93 and related roots
| Root | Simplest form | Decimal | Perfect square? |
|---|---|---|---|
| √90 | 3√10 | 9.4868 | No |
| √91 | √91 | 9.5394 | No |
| √92 | 2√23 | 9.5917 | No |
| √93 | √93 | 9.6437 | No |
| √94 | √94 | 9.6954 | No |
| √95 | √95 | 9.7468 | No |
| √96 | 4√6 | 9.7980 | No |
- The cube root of 93 is about 4.530655.
- Four times the radicand doubles the root: √372 = 2 × √93 ≈ 19.287302.
Frequently asked questions
What is the square root of 93?
The square root of 93 is √93, about 9.6436507610. The negative root, −9.643651, also squares to 93.
Is the square root of 93 rational or irrational?
Irrational. 93 is not a perfect square — it falls between 81 and 100 — and the square root of any whole number that is not a perfect square cannot be written as a fraction.
Can √93 be simplified?
No. 93 = 3 × 31 has no repeated prime factor, so there is no perfect square to take out of the radical.
What is √93 rounded to two decimal places?
√93 ≈ 9.64 to two decimal places (9.6 to one, 9.644 to three). Check: 9.64² = 92.9296, close to 93.