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Into the Exponential Distribution
Get into the exponential distribution through an exploration of its pdf.
Exponential Intersection
Stage: 5
Challenge Level:
The pdf $f(x)$ of an exponential distribution with parameter $\lambda$ is
$$f(x) = \lambda \exp(-\lambda x)\quad x\geq 0$$
The cdf $F(x)$ of such a distribution is
$$F(x) = \int^x_0 f(x') dx'$$
Use your analytical skills to answer these questions:
1. Must the pdfs of two different exponential distributions intersect?
2. In what cases do $F(x)$ and $f(x)$ intersect?
3. Can the cdfs for two exponential distributions intersect?
4. Can the pdfs for three different exponential distibutions intersect at the same point?
You might want to experiment with specific choices of $\lambda$ before constructing more general arguments.
Making and proving conjectures
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Exponential distribution
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Patterned numbers
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Probability density functions
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Inequality/inequalities
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Mathematical reasoning & proof
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Definite and indefinite integration
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Generalising
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Manipulating algebraic expressions/formulae
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Number theory
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