An object at rest will stay at rest while an object in motion will stay in motion unless acted on by an external force.
A line that intersects a curve in at least 2 points.
In a right angle triangle, the secant of an angle is the length of the hypotenuse divided by the length of the adjacent side.
The application of a force on an object that results in the displacement of the object.
The force must be applied, at least in part, in the same direction as the displacement.