√833 at a glance
- Exact value
- 7√17
- Decimal (10 places)
- 28.8617393793
- Rounded
- 28.9 · 28.86 · 28.862
- Perfect square?
- No — between 28² and 29²
- Rational?
- Irrational
- Both square roots
- ±28.861739
- Prime factorization
- 7² × 17
- Cube root
- 9.409105
How to simplify √833
Look for the largest perfect square that divides 833. Here it is 49 (7²), because 833 = 49 × 17 and 17 has no square factor left:
The prime factorization tells the same story: 833 = 7² × 17. Each pair of equal primes leaves the radical as one factor, so 7 comes out and 17 stays inside.
Check: (7√17)² = 7² × 17 = 49 × 17 = 833. As a decimal, 7√17 = 7 × 4.1231056256 ≈ 28.8617393793.
Where √833 sits between perfect squares
784 = 28² and 841 = 29² are the nearest perfect squares, so √833 lies between 28 and 29. 833 is 49 above 784 and 8 below 841, so the root is closer to 29.
- Straight line between 784 and 841: 28.8596 (0.01% low)
- Tangent from 28, i.e. 28 + 49 ÷ 56: 28.8750 (0.05% high)
- Tangent from 29, i.e. 29 − 8 ÷ 58: 28.8621 (0% high)
For √833 the tangent at 29 wins, missing by only 0.0003. Tangent estimates shine when the number sits close to a perfect square — here 833 is just 8 below 841.
Finding √833 with the Babylonian method
This is Newton’s method applied to f(x) = x² − 833: following the tangent line down to zero simplifies to averaging x with 833 ÷ x.
Start from the nearest whole number, 29 (29² = 841):
| Step | Guess x | 833 ÷ x | Average | Correct decimals |
|---|---|---|---|---|
| 1 | 29.0000000000 | 28.7241379310 | 28.8620689655 | 3 |
| 2 | 28.8620689655 | 28.8614097969 | 28.8617393812 | 8 |
| 3 | 28.8617393812 | 28.8617393774 | 28.8617393793 | 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 √833 = 28.8617393793 to every decimal shown.
√833 as a continued fraction
Every irrational square root has a continued fraction that repeats. For √833 the pattern is [28; 1, 6, 4, 3, 2, 1, 2, 1, 2, 3, 4, 6, …] with the block of 14 terms after the semicolon repeating forever (only the first 12 of the 14 are shown). A pattern that never ends is one more proof that √833 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 |
|---|---|---|
| 28/1 | 28.0000000000 | 8.6 × 10⁻¹ |
| 29/1 | 29.0000000000 | 1.4 × 10⁻¹ |
| 202/7 | 28.8571428571 | 4.6 × 10⁻³ |
| 837/29 | 28.8620689655 | 3.3 × 10⁻⁴ |
| 2,713/94 | 28.8617021277 | 3.7 × 10⁻⁵ |
| 6,263/217 | 28.8617511521 | 1.2 × 10⁻⁵ |
The same fractions solve Pell’s equation, x² − 833y² = 1. Its smallest solution in positive whole numbers is x = 9,478,657, y = 328,416.
√833 in geometry and everyday measurements
- 833 square feet is 77.4 m². Laid out as a square — a small house footprint or a lot — it is about 28.86 ft (28 ft 10 in) on a side.
- 833 = 7² + 28², so by the Pythagorean theorem √833 is the diagonal of a 7 × 28 rectangle — and the distance between the points (0, 0) and (7, 28) on a grid.
- Since √833 = 7√17, a length of √833 is exactly 7 copies of the length √17 laid end to end.
Square roots near √833 and related roots
| Root | Simplest form | Decimal | Perfect square? |
|---|---|---|---|
| √830 | √830 | 28.8097 | No |
| √831 | √831 | 28.8271 | No |
| √832 | 8√13 | 28.8444 | No |
| √833 | 7√17 | 28.8617 | No |
| √834 | √834 | 28.8791 | No |
| √835 | √835 | 28.8964 | No |
| √836 | 2√209 | 28.9137 | No |
- The cube root of 833 is about 9.409105.
- Squaring undoes the root: (√833)² = 833, while 833² = 693,889 — the number whose square root is 833.
Frequently asked questions
What is the square root of 833?
The square root of 833 is 7√17 in simplest radical form, which is about 28.8617393793. The negative root, −28.861739, also squares to 833.
Is the square root of 833 rational or irrational?
Irrational. 833 is not a perfect square — it falls between 784 and 841 — and the square root of any whole number that is not a perfect square cannot be written as a fraction.
Can √833 be simplified?
Yes. The largest perfect square dividing 833 is 49, so √833 = √49 × √17 = 7√17.
What is √833 rounded to two decimal places?
√833 ≈ 28.86 to two decimal places (28.9 to one, 28.862 to three). Check: 28.86² = 832.8996, close to 833.