How to mark parallel lines, how to show lines are parallel, and how to compare skew and parallel lines.
How to identify parallel lines, a line parallel to a plane, and two parallel planes.
How to take the converse of the parallel lines theorem.
How to find the vector and parametric equations of a line when given two points on the line.
How to find the angle of inclination of a line.
How to determine whether two lines in space are parallel or perpendicular.
How to write the vector equation of a line.
How to find the polar equation of a line through the origin (or pole).
How to write the parametric equations of a line segment that goes from point A to point B.
How to write equations describing motion in a straight line given the velocity and the position when t=0.
How to compute and simplify the difference quotient of a linear function.
How the number e is defined.
How to plot complex numbers on the complex plane.
How to understand what vectors are, and how they can be represented geometrically.
How to convert a polar equation into rectangular form.