Find all values of t such that 
is parallel to the xy-plane. 
Definitions:
Test Preparation
The process of reviewing and studying material relevant to an upcoming test or examination to improve performance.
Overlearn
The process of practicing newly acquired skills beyond the point of initial mastery, aiming to achieve automaticity.
Test-Taking Tips
Advice or strategies aimed at improving performance and reducing anxiety during exams.
Multiple-Choice
A type of question or test item that offers several answers from which one or more may be chosen as correct.
Q38: Determine the real value(s) of x for
Q43: Find the curvature of the polar curve
Q48: Find the indicated partial derivatives. <img src="https://d2lvgg3v3hfg70.cloudfront.net/TB2342/.jpg"
Q68: Explain why the function fails to be
Q75: Use the Cauchy-Schwartz Inequality in n dimensions
Q78: Match the equation to its graph. [The
Q83: Show that <img src="https://d2lvgg3v3hfg70.cloudfront.net/TB2342/.jpg" alt="Show that
Q84: Determine if the function is one-to-one. If
Q91: Find the direction of maximum change of
Q105: Find all first-order partial derivatives. <img src="https://d2lvgg3v3hfg70.cloudfront.net/TB2342/.jpg"