To calculate the logarithm base 3 of a number, you can use the change of base formula. The formula states:
- logb(a) = logc(a) / logc(b)
Here, a is the number you want to find the log of, b is the base you are converting from (in this case, 3), and c is a new base you can choose, such as 10 or e (the natural logarithm base).
For example, to calculate log3(9):
- Choose a base (let’s use 10).
- Use the change of base formula:
- log3(9) = log10(9) / log10(3)
- On your calculator, find log10(9) and log10(3).
- Calculate the values:
- log10(9) ≈ 0.9542 and log10(3) ≈ 0.4771.
- Now divide: 0.9542 / 0.4771 ≈ 2.
Thus, log3(9) = 2 because 32 = 9.
This method works for any positive number to find its logarithm base 3, allowing you to easily calculate logs without a specific base feature on your calculator.