√949 at a glance
- Exact value
- √949
- Decimal (10 places)
- 30.8058436015
- Rounded
- 30.8 · 30.81 · 30.806
- Perfect square?
- No — between 30² and 31²
- Rational?
- Irrational
- Both square roots
- ±30.805844
- Prime factorization
- 13 × 73
- Cube root
- 9.827025
How to simplify √949
The prime factorization of 949 is 13 × 73. Every prime appears only once, so there is no pair to bring outside the radical — √949 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 949, 13 and 73 appear an odd number of times, so √949 is irrational and 30.8058436015 is a rounded value.
Where √949 sits between perfect squares
900 = 30² and 961 = 31² are the nearest perfect squares, so √949 lies between 30 and 31. 949 is 49 above 900 and 12 below 961, so the root is closer to 31.
- Straight line between 900 and 961: 30.8033 (0.01% low)
- Tangent from 30, i.e. 30 + 49 ÷ 60: 30.8167 (0.04% high)
- Tangent from 31, i.e. 31 − 12 ÷ 62: 30.8065 (0% high)
For √949 the tangent at 31 wins, missing by only 0.0006. Tangent estimates shine when the number sits close to a perfect square — here 949 is just 12 below 961.
Finding √949 with the Babylonian method
This is Newton’s method applied to f(x) = x² − 949: following the tangent line down to zero simplifies to averaging x with 949 ÷ x.
Start from the nearest whole number, 31 (31² = 961):
| Step | Guess x | 949 ÷ x | Average | Correct decimals |
|---|---|---|---|---|
| 1 | 31.0000000000 | 30.6129032258 | 30.8064516129 | 3 |
| 2 | 30.8064516129 | 30.8052356021 | 30.8058436075 | 8 |
| 3 | 30.8058436075 | 30.8058435955 | 30.8058436015 | all 10 shown |
The count of correct decimals went 3, 8 and all 10 over 3 steps — roughly doubling each time — until the guess matched √949 = 30.8058436015 to every decimal shown.
√949 as a continued fraction
Every irrational square root has a continued fraction that repeats. For √949 the pattern is [30; 1, 4, 6, 1, 1, 1, 4, 2, 14, 1, 19, 1, …] with the block of 27 terms after the semicolon repeating forever (only the first 12 of the 27 are shown). A pattern that never ends is one more proof that √949 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 |
|---|---|---|
| 30/1 | 30.0000000000 | 8.1 × 10⁻¹ |
| 31/1 | 31.0000000000 | 1.9 × 10⁻¹ |
| 154/5 | 30.8000000000 | 5.8 × 10⁻³ |
| 955/31 | 30.8064516129 | 6.1 × 10⁻⁴ |
| 1,109/36 | 30.8055555556 | 2.9 × 10⁻⁴ |
| 2,064/67 | 30.8059701493 | 1.3 × 10⁻⁴ |
The same fractions solve Pell’s equation, x² − 949y² = 1. Its smallest solution in positive whole numbers is x = 609,622,436,806,639,069,525,576,201, y = 19,789,181,711,517,243,032,971,740 — 27 digits for x, even though 949 is small, which is what makes Pell’s equation famous. Because the period is odd, the equation with −1 on the right also has a solution: 17,458,843,558,590² − 949 × 566,738,044,393² = −1.
√949 in geometry and everyday measurements
- 949 square feet is 88.2 m². Laid out as a square — a small house footprint or a lot — it is about 30.81 ft (30 ft 10 in) on a side.
- 949 = 7² + 30² = 18² + 25², so by the Pythagorean theorem √949 is the diagonal of rectangles measuring 7 × 30 and 18 × 25 — and the distance between the points (0, 0) and (7, 30) on a grid.
Square roots near √949 and related roots
| Root | Simplest form | Decimal | Perfect square? |
|---|---|---|---|
| √946 | √946 | 30.7571 | No |
| √947 | √947 | 30.7734 | No |
| √948 | 2√237 | 30.7896 | No |
| √949 | √949 | 30.8058 | No |
| √950 | 5√38 | 30.8221 | No |
| √951 | √951 | 30.8383 | No |
| √952 | 2√238 | 30.8545 | No |
- The cube root of 949 is about 9.827025.
- Squaring undoes the root: (√949)² = 949, while 949² = 900,601 — the number whose square root is 949.
Frequently asked questions
What is the square root of 949?
The square root of 949 is √949, about 30.8058436015. The negative root, −30.805844, also squares to 949.
Is the square root of 949 rational or irrational?
Irrational. 949 is not a perfect square — it falls between 900 and 961 — and the square root of any whole number that is not a perfect square cannot be written as a fraction.
Can √949 be simplified?
No. 949 = 13 × 73 has no repeated prime factor, so there is no perfect square to take out of the radical.
What is √949 rounded to two decimal places?
√949 ≈ 30.81 to two decimal places (30.8 to one, 30.806 to three). Check: 30.81² = 949.2561, close to 949.