Archives for March 2012
We can check if the given number is divisible by 2, 3, 4, 5, 6, 7, 8, 9, 10 or 11 through divisibility tests. Each test is easy to perform on a given number except divisibility test of 7 which is harder as comparing to others. Go through the files and learn different divisibility tests. They can really help you in doing different calculations quickly.
We can solve linear system of equations using Cramer's rule which is one of the applications of determinants. We just need to find values of different determinants in order to solve system of equaltions. From the values of these determinants, we can know if the equations are consistent or inconsistent.
There are many applications of matrices and determinants. One of the application is to find area of triangle if we are given with vertices of triangle.
This post is dedicated to some important properties regarding adjoint of matrix. If, you want to go through their proves then click particular property. Note that these properties are only valid for square matrices as adjoint is only valid for square matrices.
(1) where, A is a square matrix, I is an identity matrix of same order as of A and represents determinant of matrix A.
(2) determinant of adjoint A is equal to determinant of A power n-1 where A is invertible n x n square matrix.
You can also take examples to verify these properties.