\documentclass{article}
\usepackage{amsmath}
\newcommand{\rr}{\mathbf{r}}
\newcommand{\ii}{\mathbf{i}}
\newcommand{\jj}{\mathbf{j}}
\newcommand{\kk}{\mathbf{k}}
\begin{document}
{\bf Quiz \#5; Tuesday, date: 02/20/2018}
{\bf MATH 53 Multivariable Calculus with Stankova}
{\bf Section \#117; time: 5 -- 6:30 pm}
{\bf GSI name: Kenneth Hung}
{\bf Student name:}
\vspace*{0.25in}
\begin{enumerate}
\item Find the tangential and normal components of the acceleration vector.
\[
\rr(t) = t \ii + 4e^{t/2} \jj + 2e^t \kk
\]
\item {\em True / False?} Suppose the curve $\rr(t)$ goes through the origin. A new curve formed by shrinking the curve $\rr(t)$ towards the origin by a factor of $2$. (In other words, a point $\mathbf{v}$ is shrunk to $\mathbf{v} / 2$.) The curvature is multiplied by a factor of $2$ as well.
\item {\em True / False?} For a smooth space curve $\rr(t)$ that is on the $x, y$-plane, the binormal vector (when defined) must either be $\kk$ for all $t$ or $-\kk$ for all $t$, depending on which way the curve is traversed.
\end{enumerate}
\end{document}