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@@ -12,7 +12,7 @@
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This chapter introduces the theoretical foundations for the work presented in
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this thesis. In~\Cref{sec:domain} and~\Cref{sec:differentialEq}, we describe
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-differential equations and the underlying theory. In these Sections both the
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+differential equations and the underlying theory. In these Sections, both the
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explanations and the approach are based on a book on analysis by
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Rudin~\cite{Rudin2007} and a book about ordinary differential equations by
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Tenenbaum and Pollard~\cite{Tenenbaum1985}. Subsequently, we employ this
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@@ -36,7 +36,7 @@ numbers in $\mathbb{R}$.\\
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The mapping between variables enables the modeling of a physical process and may
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depict semantics. We use functions in order to facilitate this mapping. Let
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-$A, B\subset\mathbb{R}$ be to subsets of the real numbers, then we define a
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+$A, B\subset\mathbb{R}$ be two subsets of the real numbers, then we define a
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function as the mapping
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\begin{equation}
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f: A\rightarrow B.
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@@ -55,24 +55,24 @@ In this case, time serves as the domain, while the distance is the codomain.
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Often, the behavior of a variable or a quantity across a domain is more
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interesting than its current state. Functions are able to give us the latter,
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-but do not contain information about the change of a system. The objective
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+but do not contain any information about the change of a system. The objective
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is to determine an effective method for calculating the change of a function
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across its domain. Let $f$ be a function and $[a, b]\subset \mathbb{R}$ an
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interval of real numbers. The expression
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\begin{equation}
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- m = \frac{f(b) - f(a)}{a-b}
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+ m = \frac{f(b) - f(a)}{b-a}
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\end{equation}
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gives the average rate of change. While the average rate of change is useful in
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many cases, the momentary rate of change is more accurate. To calculate the
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-momentary rate of change at $x$, we let the value $t$ approach $x$ thereby
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-narrowing down the interval to an infinitesimal. For each $x\in[a, b]$ we
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+momentary rate of change at $x$, we let the value $t$ approach $x$ and thereby
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+narrow down the interval to an infinitesimal. For each $x\in[a, b]$ we
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calculate
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\begin{equation} \label{eqn:differential}
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\frac{df}{dx} = \lim_{t\to x} \frac{f(t) - f(x)}{t-x},
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\end{equation}
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if it exists. As the Tenenbaum and Pollard~\cite{Tenenbaum1985} define,
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$\nicefrac{df}{dx}$ is the \emph{derivative}, which is ``the rate of change of a
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-variable with respect to another''. The relation between a variable and its
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+variable with respect to another''~\cite{Tenenbaum1985}. The relation between a variable and its
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derivative is modeled in a \emph{differential equation}. The derivative of
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$\nicefrac{df}{dx}$ yields $\nicefrac{d^2f}{dx^2}$, which is the function that
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calculates the rate of change of the rate of change and is called the
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@@ -97,17 +97,17 @@ Another example would be a function, that maps its inputs of a location variable
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and a time variable on a height. The term \emph{partial differential equations}
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(PDE) describes differential equations of such functions, which contain
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partial derivatives with respect to each individual domain. In contrast,
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-\emph{ordinary differential equations} (ODE) are the single derivatives for a
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+\emph{ordinary differential equations} (ODE) contain derivatives for a
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function having only one domain~\cite{Tenenbaum1985}. In this thesis, we
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restrict ourselves to ODE's. Furthermore, a
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\emph{system of differential equations} is the name for a set of differential
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-equations. The derivatives in a system of differential equations each have their
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+equations. The equations in a system of differential equations each have their
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own codomain, which is part of the problem, while they all share the same
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domain.\\
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Tenenbaum and Pollard~\cite{Tenenbaum1985} provide many examples for ODE's,
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-including the \emph{Motion of a Particle Along a Straight Line}. Further,
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-Newton's second law states that ``the rate of change of the momentum of a body
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+including the \emph{Motion of a Particle Along a Straight Line}. This example is based on
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+Newton's second law which states that ``the rate of change of the momentum of a body
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($momentum = mass \cdot velocity$) is proportional to the resultant external
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force $F$ acted upon it''~\cite{Tenenbaum1985}. Let $m$ be the mass of the body
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in kilograms, $v$ its velocity in meters per second and $t$ the time in seconds.
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