The identity matrix is a square matrix which has 1 for every element in the main diagonal and 0 for every other element. The identity matrix plays the role of the identity under multiplication, just like number 1 is with numbers. Two square matrices A and B are inverses of each other if their product is an identity matrix. To compare this with numbers, number 2 and 1/2 are inverses of each other because their product is 1. A square matrix has an inverse if and only if its determinant is not zero. The inverse of a 2 x 2 determinant can be calculated using a specific formula. Dive into the lecture and learn more about identity and inverse matrices.
*These practice questions are only helpful when you work on them offline on a piece of paper and then use the solution steps function to check your answer.
Identity and Inverse Matrices
Lecture Slides are screen-captured images of important points in the lecture. Students can download and print out these lecture slide images to do practice problems as well as take notes while watching the lecture.