Mistake Master
Mistake Master · AP Precalculus · Unit 4 · Step-Through Animation
Motion Becomes Arithmetic
You'll learnto turn questions about motion into vector arithmetic.
A vector-valued function hands every value of the parameter a whole position, so questions about motion turn into vector arithmetic: where it went is a subtraction, how far apart the ends are is a magnitude, and which way it is heading is the direction of a change vector. The traps are all lane violations.
Unit 4 is not assessed on the AP exam; schools include it where local requirements ask.
arrowheads show each vector’s direction
Before you start
What you're looking at
A person's position at two times, with distinct arrows for position, displacement, and the path.
The question
Where did it go, how far apart are the ends, and which way is it heading?
Watch for
Position (origin to point), displacement (point to point), and path kept visually distinct — with units added for speed.
Step 1 / 8