A matrix is an ordered rectangular array of numbers or functions. The numbers or functions are called the elements or the entries of the matrix. We denote matrices by capital letters. The following are some examples of matrices:
A =`[(-2,5),(0, sqrt 5) , (3,6)] , B = [(2+i,3 , -1/2),(3.5,-1,2),(sqrt3 , 5 , 5/7)] , C = [(1+x , x^3,3),(cos x , sin x + 2 , tan x)]`
In the above examples, the horizontal lines of elements are said to constitute, rows of the matrix and the vertical lines of elements are said to constitute, columns of the matrix. Thus A has 3 rows and 2 columns, B has 3 rows and 3 columns while C has 2 rows and 3 columns.
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