Let (m × n) denote a matrix of size m × n. Find the size of the following product, or state that the product is not defined.
-(3 × 4)(3 × 4)
A)3 × 4
B)3 × 3
C)4 × 3
D)not defined

Question

Quizplus · Accepted Answer

For matrix multiplication to be defined, the number of columns in the first matrix must equal the number of rows in the second matrix. Since the first matrix is 3 × 4 and the second matrix is also 3 × 4, the number of columns in the first matrix (4) does not match the number of rows in the second matrix (3), making the product undefined.

Let (M × N) Denote a Matrix of Size M