Determinants are numbers associated with square matrices and written using vertical bars. To define determinants, we start out with 2x2 matrix, whose determinant is called a second-order determinant. We find this determinant using a formula that you can see in the lecture. A determinant of a 3x3 matrix is more complex and there are a couple of methods to evaluate it. The first method is called expansion by minors and its goal is to expand the 3x3 determinant into three 2x2 determinants. The second method is called the diagonal method. The determinant is found by calculating products of entries along the diagonals and then adding and subtracting these products.
*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.
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.