The exponential function ex uses the mathematical constant e (≈ 2.71828) as its base. It describes continuous growth and decay processes — population growth, radioactive decay, compound interest, and thermal cooling all follow exponential patterns.
Key properties of ex:
Inverse of natural logarithm: If ex = y, then ln(y) = x. These two functions undo each other.
Derivative equals itself: d/dx(ex) = ex. The exponential function is its own derivative — unique among all functions.
Power properties: ea x eb = ea+b. (ea)b = eab.
e0 = 1: Any number raised to the zero power equals 1.
Negative exponents: e-x = 1/ex.
Finance: Compound interest, continuous compounding, option pricing models.
Biology: Population growth models, bacterial colony expansion, drug half-life in the bloodstream.
Physics: Radioactive decay, capacitor charge/discharge, Newton's law of cooling.
Engineering: Signal processing, control systems, damping in mechanical systems.
Computer Science: Machine learning activation functions, cryptographic algorithms, complexity analysis.