asked 123k views
0 votes
Suppose A=[[3,5],[2,4]] and B=[[2,-2.5],[-1,1.5]]

a. Compute AB and BA, if possible.
b. What is the relationship between A and B?

asked
User Slaakso
by
8.3k points

1 Answer

6 votes

Final answer:

Matrices A and B are inverse matrices of each other as their products AB and BA both result in the identity matrix.

Step-by-step explanation:

The question requires us to perform matrix multiplication of two given matrices A and B, and then analyze their relationship. For two matrices A and B, where A=[[3,5],[2,4]] and B=[[2,-2.5],[-1,1.5]], the products AB and BA are calculated as follows:

To compute AB, we multiply each element of the rows of A by the corresponding element of the columns of B, and then sum those products for each position in the resulting matrix:

AB = [[(3*2 + 5*(-1)), (3*(-2.5) + 5*1.5)], [(2*2 + 4*(-1)), (2*(-2.5) + 4*1.5)]]
= [[6 - 5, -7.5 + 7.5], [4 - 4, -5 + 6]]
= [[1, 0], [0, 1]]

To compute BA, we apply the same process, multiplying each element of the rows of B by the corresponding elements of the columns of A:

BA = [[(2*3 + -2.5*2), (2*5 + -2.5*4)], [(-1*3 + 1.5*2), (-1*5 + 1.5*4)]]
= [[6 - 5, 10 - 10], [-3 + 3, -5 + 6]]
= [[1, 0], [0, 1]]

After computing AB and BA, we observe that both products resulted in the identity matrix, which indicates a certain relationship known as inverse matrices. Matrices A and B are inverses of each other because when they are multiplied in either order, the result is the identity matrix.

answered
User Dmitry Sikorsky
by
7.9k points

No related questions found

Welcome to Qamnty — a place to ask, share, and grow together. Join our community and get real answers from real people.