Proof: Probability density function of the exponential distribution
	
	
	Index:
	The Book of Statistical Proofs ▷
	Probability Distributions ▷
	Univariate continuous distributions ▷
	Exponential distribution ▷
	Probability density function 
	
	
	
Metadata: ID: P46 | shortcut: exp-pdf | author: JoramSoch | date: 2020-02-08, 23:53.
  
  
  
Theorem: Let $X$ be a non-negative random variable following an exponential distribution:
\[\label{eq:exp} X \sim \mathrm{Exp}(\lambda) \; .\]Then, the probability density function of $X$ is
\[\label{eq:gam-pdf} f_X(x) = \lambda \exp[-\lambda x] \; .\]Proof: This follows directly from the definition of the exponential distribution.
∎
	
	
	
	  Sources: Metadata: ID: P46 | shortcut: exp-pdf | author: JoramSoch | date: 2020-02-08, 23:53.