Mistake Master
Mistake Master · AP Precalculus · Unit 4 · Step-Through Animation
Row Meets Column
You'll learnto multiply matrices as a row-by-column machine.
Most matrix arithmetic behaves exactly as you would guess: addition and scalar multiplication act entry by entry. The one operation that refuses to be guessed is the product, a row-by-column machine with its own dimension rule and no tolerance for the shortcuts that work on ordinary numbers. Twelve short steps; press Next for each one.
Unit 4 is not assessed on the AP exam; schools include it where local requirements ask.
the blue band is a row, the pink band is a column
Before you start
What you're looking at
A small table of two students' scores on three assignments, read for its rows and columns.
The question
How does a single entry of a matrix product get built?