Determinants
We define the determinant of a 2×2 matrix as the curiously cross product.
3 × 3 Determinants
Each element, or number, in this determinant is associated with determinant called its minor. The minor of an element is the determinant that remains when you cross out the row and column containing that element.
You can evaluate a 3 × 3determinant by expanding by the minors of the elements in any row or column.
The evaluation of determinants can be made easier by transforming the determinant into an equivalent one in which a row (column) has several zero elements. To do this, multiply any row(column)by a constant and add the resulting products to the elements of another row (column).
Learn more about determinants by reading the explanation below.
Practice: Answer the following exercises by finding the determinant of a matrix.