Root Calculator
x1/n = Result
Example:
If x = 16 and n = 2 (Square Root):
161/2 = 4
In mathematics, the general root, or the nth root of a number a is another number b that when multiplied by itself n times, equals a. In equation format:
n√a = b
bn = a
Estimating a Root
Some common roots include the square root, where n = 2, and the cubed root, where n = 3. Calculating square roots and nth roots is fairly intensive. It requires estimation and trial and error. There exist more precise and efficient ways to calculate square roots, but below is a method that does not require a significant understanding of more complicated math concepts. To calculate √a:
- Estimate a number b
- Divide a by b. If the number c returned is precise to the desired decimal place, stop.
- Average b and c and use the result as a new guess
- Repeat step two
EX: | Find √27 to 3 decimal places |
Guess: 5.125 27 ÷ 5.125 = 5.268 (5.125 + 5.268)/2 = 5.197 27 ÷ 5.197 = 5.195 (5.195 + 5.197)/2 = 5.196 27 ÷ 5.196 = 5.196 |
Estimating an nth Root
Calculating nth roots can be done using a similar method, with modifications to deal with n. While computing square roots entirely by hand is tedious. Estimating higher nth roots, even if using a calculator for intermediary steps, is significantly more tedious. For those with an understanding of series, refer here for a more mathematical algorithm for calculating nth roots. For a simpler, but less efficient method, continue to the following steps and example. To calculate n√a:
- Estimate a number b
- Divide a by bn-1. If the number c returned is precise to the desired decimal place, stop.
- Average: [b × (n-1) + c] / n
- Repeat step two
EX: | Find 8√15 to 3 decimal places |
Guess: 1.432 15 ÷ 1.4327 = 1.405 (1.432 × 7 + 1.405)/8 = 1.388 15 ÷ 1.3887 = 1.403 (1.403 × 7 + 1.388)/8 = 1.402 |
It should then be clear that computing any further will result in a number that would round to 1.403, making 1.403 the final estimate to 3 decimal places.
How to do square root on calculator?
1. Locate the Square Root Key:
- Most scientific calculators have a dedicated square root key, which looks like this: “√”
- Sometimes, it might be a secondary function, often above the “x²” key. In this case, you’ll need to press the “shift” or “2nd” key first.
2. Enter the Number:
- Type in the number you want to find the square root of.
3. Press the Square Root Key:
- Press the “√” key.
- If it’s a secondary function, press “shift” or “2nd” and then the key with the square root symbol.
4. View the Result:
- The calculator will display the square root of the number.
Example:
To find the square root of 25:
- Type “25”
- Press “√”
- The calculator will display “5”
Important Notes:
- Negative Numbers: If you try to take the square root of a negative number on most basic calculators, you’ll get an error, as the result is an imaginary number. Some advanced calculators can handle complex numbers.
- Decimal Places: The calculator will usually display the result with several decimal places.