Difference between revisions of "Real numbers"

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|[[Delta_integral | $\Delta$-integral:]]
 
|[[Delta_integral | $\Delta$-integral:]]
| $\displaystyle\int_s^t f(\tau) \Delta \tau = \displaystyle\int_s^t f(\tau) d\tau$ is the Riemann integral
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| $\displaystyle\int_s^t f(\tau) \Delta \tau = \displaystyle\int_s^t f(\tau) d\tau$ is the [http://en.wikipedia.org/wiki/Riemann_integral Riemann integral]
 
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|[[Exponential_functions | Exponential function]]:
 
|[[Exponential_functions | Exponential function]]:

Revision as of 04:17, 18 May 2014

The set $\mathbb{R}$ of real numbers is a time scale.

$\mathbb{T}=\mathbb{R}$
Generic element $t \in \mathbb{T}$: $t=t$
Jump operator: $\sigma(t)=t$
Graininess operator: $\mu(t)=0$
$\Delta$-derivative: $f^{\Delta}(t)=\displaystyle\lim_{h\rightarrow 0} \dfrac{f(t+h)-f(t)}{h}$
$\Delta$-integral: $\displaystyle\int_s^t f(\tau) \Delta \tau = \displaystyle\int_s^t f(\tau) d\tau$ is the Riemann integral
Exponential function: $\begin{array}{ll} e_p(t,s) &= \exp \left( \displaystyle\int_s^t \displaystyle\lim_{h \rightarrow 0} \dfrac{1}{h} \log(1 + hp(\tau)) d\tau \right) \\ &\hspace{-10pt} \stackrel{\mathrm{L'Hôpital}}{=} \exp \left( \displaystyle\int_s^t \displaystyle\lim_{h \rightarrow 0} \dfrac{1}{1+hp(\tau)} p(\tau) d\tau \right) \\ &= \exp \left( \displaystyle\int_s^t p(\tau) d \tau \right) \end{array}$