Most graphing calculators only include keys for base 10 or base "e" logarithms. In order to use other bases, you'll have to take advantage of the change of base formula. Before handheld calculators were the norm, accountants, scientists and engineers used logarithms to multiply and divide large numbers. Now, logarithms are still taught in schools due to their usefulness in science and statistics. For example, scientists use the Richter scale, which is logarithmic, to measure the magnitude of earthquakes.
Instructions
1. Identify the base of your logarithm. The base is written in subscript next to the log. Assume any logarithm without a subscript is logarithm base 10. For example, the base of Log2(35) is 2.
2. Identify the number you are taking the logarithm of. This is written in parenthesis next to the log. In the expression Log2(35), you're taking the logarithm of 35.
3. Press the "Log" key on your graphing calculator. Enter the number you're taking the logarithm of. If you wanted to find the value of Log2(35), you would enter "Log 35."
4. Press the division key.
5. Press the "Log" key and enter the base of the logarithm. To find the value of Log2(35), you would enter "Log 2".
6. Press the "Enter" key. The calculator will output the value.
Tips & Warnings
- You can use either logarithm base 10 or the natural logarithm to do this calculation, both will result in the same answer.
- The natural logarithm uses Euler's number, "e", as a base. "e" is approximately 2.718.
- Mathematicians write "Log" without a superscript to signify the natural logarithm. Others, such as scientists, use that to denote logarithms in base 10.
No comments:
Post a Comment