Calculatrice de Logarithme Gratuite
Calculez les logarithmes en base 10, naturels (ln) ou dans n'importe quelle base. Résolvez des problèmes logarithmiques.
Log10 Val
2.000000
Ln Val4.605170
Formule
How Logarithms Work
Definition
log_b(x) = y means b^y = x
The logarithm answers: "To what power must I raise the base to get this number?"
Common Types
Change of Base Formula
log_b(x) = ln(x) / ln(b)
Exemple Résolu
Calculate the logarithms of 100.
- 01log₁₀(100) = 2 (because 10² = 100)
- 02ln(100) ≈ 4.605170
- 03log₂(100) = ln(100)/ln(2) ≈ 6.643856
Questions Fréquentes
What is a logarithm?
A logarithm is the inverse of exponentiation. log_b(x) answers the question: what power of b gives x?
What is the difference between log and ln?
log (or log₁₀) uses base 10 and is common in science and engineering. ln uses base e (≈2.718) and is the natural logarithm used in calculus.
Can you take the log of a negative number?
Not in the real number system. Logarithms are only defined for positive real numbers. The complex logarithm extends this to negative numbers.
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