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 lnx, 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 lna.
Key properties of the natural logarithm include:
- e^ln(a) = a for any positive real number a
- lneb = b for any real number b
- lne = 1
The function's behavior is characterized by:
- ln1 = 0
- For 0 < x < 1, lnx < 0
- For x > 1, lnx > 0
Highlight: The natural logarithm function is strictly increasing on its domain 0,+∞.
The page also includes a graph illustrating the shape of the lnx function, which is crucial for understanding its behavior visually.
Example: ln1/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.