Logarithme Népérien (Natural Logarithm)
This page introduces the natural logarithm function, its definition, and key properties. The fonction logarithme népérien is a crucial concept in advanced mathematics and calculus.
The natural logarithm, denoted as ln(x), is defined as the inverse function of e^x. It is defined for all positive real numbers (x > 0).
Definition: For any real number a > 0, the equation e^x = a has a unique solution called ln(a).
Key properties of the natural logarithm include:
- e^(ln(a)) = a for any positive real number a
- ln(e^b) = b for any real number b
- ln(e) = 1
The function's behavior is characterized by:
- ln(1) = 0
- For 0 < x < 1, ln(x) < 0
- For x > 1, ln(x) > 0
Highlight: The natural logarithm function is strictly increasing on its domain (0, +∞).
The page also includes a graph illustrating the shape of the ln(x) function, which is crucial for understanding its behavior visually.
Example: ln(1/e) = -1, demonstrating how the function behaves for values between 0 and 1.
These propriétés logarithme népérien form the foundation for more advanced applications and problem-solving techniques involving logarithms.