Calculating the Square Root of 0.9: A Comprehensive Guide

Calculating the Square Root of 0.9: A Comprehensive Guide

The square root of a number is a value that, when multiplied by itself, gives the original number. When it comes to the number 0.9, it is not a perfect square, but we can find its square root using various methods. This guide will explore these methods and provide detailed explanations.

Method 1: Direct Calculation and Approximation

One of the direct ways to find the square root of 0.9 is by using a simple fraction and decimal approximation. Here's how you can do it:

Write 0.9 as a fraction: 0.9 9/10. Take the square root of the fraction: √(9/10) √9/√10 3/√10. Simplify the expression by multiplying the numerator and the denominator by the square root of 10: (3/√10) * (√10/√10) 3√10/10. Use a calculator or a known approximation to find the value: √10 ≈ 3.162, so 3√10/10 ≈ 3 * 3.162 / 10 0.948683298.

Method 2: Using Logarithms

Another method involves using logarithms to find the square root of 0.9. Here's the detailed process:

Let n √0.9. Take the natural logarithm (ln) of both sides: ln n ln 0.9^0.5. Simplify using logarithm properties: ln n 0.5 * ln 0.9. Calculate the value of ln 0.9: ln 0.9 ≈ -0.05268025782891315061375049041966. Solve for n: ln n 0.5 * (-0.05268025782891315061375049041966) -0.02634012891445657530687524520983. Exponentiate both sides to find n: n e^(-0.02634012891445657530687524520983) ≈ 0.94868329805.

Method 3: Window Calculator Result

For a straightforward approach, you can use the Windows Calculator to find the square root of 0.9:

Use the Windows Calculator and check the result: √0.9 ≈ 0.94868329805.

Multiple Methods for Approximation

There are several ways to approximate the square root of 0.9:

Direct multiplication: 3√10/10 ≈ 3 * 3.162 / 10 0.94868329805. Negative approximation: -0.3√10 ≈ -0.3 * 3.162 0.9486, or approximately -0.95.

Step-by-Step Square Root Approximation

Here's a detailed step-by-step method to approximate the square root of 0.9:

Assume n 0.9^0.5 90/100^0.5 1/10 * 90^0.5. Knowing that 9^2 81 and 10^2 100, the square root of 90 lies between 9 and 10. Assume the square root is 9 h where 0 h 1. Solve for h: (9 h)^2 90. Rearrange the equation: 81 18h h^2 90. Neglect h^2 (since h is very small): 81 18h 90. Isolate h: 18h 90 - 81 9. Solve for h: h 9/18 0.5. Check the value: (9 0.5)^2 90.25, which is close but not exact. Repeat the process: (9.5 - 0.01316)^2 90. Thus, the square root of 90 is approximately 9.48684.

Conclusion

The square root of 0.9 can be found using multiple methods, including direct calculation, logarithms, and step-by-step approximation. By following these techniques, you can accurately determine the square root of any given number.

Keywords Related to This Topic

Square root 0.9 Approximation