[tex]\bf \qquad \textit{Amount for Exponential Decay}
\\\\
A=a(b)^x\qquad
\begin{cases}
A=\textit{accumulated amount}\\
a=\textit{initial amount}\\
b=\textit{decay factor}\\
x=\textit{elapsed time}\\
\end{cases}
\\\\\\
y=\stackrel{a}{5}(\stackrel{b}{0.5})^x[/tex]
