Logarithm Calculation Formula:
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A logarithm is the inverse operation to exponentiation, answering the question "to what power must the base be raised to produce a given number?" For example, log₃(9) = 2 because 3² = 9.
The calculator uses the logarithm change of base formula:
Example Calculation:
Applications: Logarithms are fundamental in mathematics, science, engineering, and computer science. They're used in measuring earthquake intensity (Richter scale), sound intensity (decibels), and in algorithms for efficient computation.
Instructions: Enter any positive number and base (≠1) to calculate the logarithm. The calculator will show the result and step-by-step solution.
Q1: Why is ln used in the formula?
A: Natural logarithm (ln) can be used with any base via the change of base formula. Calculators typically have ln and log₁₀ functions built-in.
Q2: What if the base is 1?
A: Logarithm with base 1 is undefined because 1 raised to any power is always 1.
Q3: Can I calculate logarithms of negative numbers?
A: No, logarithms are only defined for positive real numbers in real number system.
Q4: What's the difference between ln and log?
A: ln is logarithm with base e (≈2.718), while log typically means log₁₀ unless specified otherwise.
Q5: How accurate is this calculation?
A: The calculation uses PHP's built-in log function which provides high precision (about 14 decimal digits).