Chapter 11 Matrices

Question 1

Adding and Subtracting Matrices

Answer 1

A matrix can only be added to (or subtracted from) another matrix if the two matrices have the same dimensions . To add two matrices, just add the corresponding entries, and place this sum in the corresponding position in the matrix which results.

Question 2

Multiplying Matrices

Answer 2

Can only work if C = C in the R x C of Matrix 1 and R x C of Matrix 2,

Question 3

Matrix Algebra vs Ordinary Algebra

Answer 3

Question 4

Inverse of a 2x2 Matrix

Answer 4

To find the inverse of a 2x2 matrix: swap the positions of a and d, put negatives in front of b and c, and divide everything by the determinant (ad-bc).

Considering the Matrix is A B
C D

Question 5

Further Matrices Algebra

Answer 5

Question 6

Finding a determinant of a 3x3 matrix

Answer 6

Hide the row and column of the 2x2 determinant you’re finding

Question 7

Inverse of 3x3 Matrix using Adjugate Pt.1

Answer 7

Transpose the matrix first, then find the determinant of 2x2 matrices

Question 8

Inverse of a 3x3 Matrix using Adjugate

Answer 8

Those + - symbols will stay constant and add to the adjugate,

To find determinant look at white pic, keep in mind the + - symbols