Notes (Solutions) of Chapter 02: Matrices and Determinants, Text Book of Algebra and Trigonometry Class XI (Mathematics FSc Part 1 or HSSC-I), National Foundation Book.

A very common use of matrices in daily life is encryption. We use them to scramble data for security purpose and to encode and decode this data. There is a key that helps encode and decode data which is generated by matrices. The screen of any electronic device, like smart phone or LED TV screen is essentially a pixel matrix. When we rotate the phone and it is in landscape form. The matrix is actually rotated using the transpose. When we touch the screen of a cell phone at some specific position; the position is calculated by matrix properties.

A matrix is an array or number arranged in horizontal and vertical lines enclosed within square brackets, Matrices are usually denoted with capital letters. The horizontal lines are known as rows of the matrix and vertical lines are known as columns of the matrix.