Matrix Test Review

Front

What must be true in order to ADD two matrices?

Back

The dimensions must be the same.

Front

What is the result of B - A if B = [[1, 0], [1, -4]] and A = [[-3, 1], [7, -1]]?

Back

B - A = [[4, 0], [-6, 1]]

Front

To DECRYPT a message matrix A using an encryption matrix E, you multiply by which matrix?

Back

You multiply by the inverse of E, denoted as E^{-1}.

Front

What is the requirement for two matrices to be added together?

Back

They must have the same dimensions.

Front

What is the result of adding the matrices [[11, 8], [-4, 2]] and [[3, 2], [-6, -6]]?

Back

The result is [[14, 10], [-10, -4]].

Front

What is the formula for matrix multiplication?

Back

If A is an m x n matrix and B is an n x p matrix, then the product AB is an m x p matrix.

Front

What does it mean for a matrix to be invertible?

Back

A matrix is invertible if there exists another matrix such that their product is the identity matrix.

Front

What is the identity matrix?

Back

The identity matrix is a square matrix with ones on the diagonal and zeros elsewhere.

Front

How do you find the determinant of a 2x2 matrix [[a, b], [c, d]]?

Back

The determinant is calculated as ad - bc.

Front

What is the result of multiplying a matrix by its inverse?

Back

The result is the identity matrix.