{"id":4883,"date":"2021-08-31T12:57:40","date_gmt":"2021-08-31T12:57:40","guid":{"rendered":"https:\/\/mathemerize.com\/?p=4883"},"modified":"2022-01-16T17:00:03","modified_gmt":"2022-01-16T11:30:03","slug":"scalar-multiplication-with-matrices","status":"publish","type":"post","link":"https:\/\/mathemerize.com\/scalar-multiplication-with-matrices\/","title":{"rendered":"Scalar Multiplication with Matrices – Properties and Examples"},"content":{"rendered":"
Here you will learn scalar multiplication with matrices (multiplicaition of a matrix by a scalar ) and properties of scalar mutiplication.<\/p>\n
Let’s begin – <\/p>\n
Definition : <\/strong>Let \\([a_{ij}]\\) be an \\(m\\times n\\) matrix and k be any number called a scalar. Then the matrix obtained by mutiplying every element of A by k is called the scalar multiple of A by k and is denoted by kA.<\/p>\n Thus, <\/p>\n kA = \\([ka_{ij}]_{m\\times n}\\)<\/p>\n<\/blockquote>\n Example : <\/span><\/strong>if A = \\(\\begin{bmatrix} 1 & 2 & 5 \\\\ -2 & 3 & 4 \\\\ 1 & 2 & -1 \\end{bmatrix}\\), then 3A = \\(\\begin{bmatrix} 3 & 6 & 15 \\\\ -6 & 9 & 12 \\\\ 3 & 6 & -3 \\end{bmatrix}\\)<\/p>\n <\/span><\/strong>if A = \\(\\begin{bmatrix} 6 & 2 & 3 \\\\ 2 & 3 & -2 \\\\ 2 & 4 & 1 \\end{bmatrix}\\), then \\(1\\over 2\\)A = \\(\\begin{bmatrix} 3 & 1 & 3\/2 \\\\ 1 & 3\/2 & -1 \\\\ 1 & 2 & 1\/2 \\end{bmatrix}\\)<\/p>\n Example : <\/span><\/strong> Let A = \\(\\begin{bmatrix} 1 & 5 & 7 & 3\\\\ -1 & 5 & 9 & 4 \\\\ -2 & 6 & 3 & -5 \\end{bmatrix}\\), then 2A = \\(\\begin{bmatrix} 2 & 10 & 14 & 6\\\\ -2 & 10 & 18 & 8 \\\\ -4 & 12 & 6 & -10 \\end{bmatrix}\\)<\/p>\n and \\(1\\over 2\\)A = \\(\\begin{bmatrix} 1\/2 & 5\/2 & 7\/2 & 3\/2 \\\\ -1\/2 & 5\/2 & 9\/2 & 2 \\\\ -1 & 3 & 3\/2 & -5\/2 \\end{bmatrix}\\)<\/p>\n Various properties of scalar multiplication are stated below :<\/p>\n If A = \\([a_{ij}]_{m\\times n}\\), B = \\([b_{ij}]_{m\\times n}\\) are two matrices and k and l are scalars, then<\/p>\n (i) k (A + B) = k A + k B<\/p>\n (ii) (k + l) A = k A + l A<\/p>\n (iii) (k l) A = k (l A) = l (k A)<\/p>\n (iv) (-k) A = – (k A) = k(-A)<\/p>\n (v) 1 A = A<\/p>\n (vi) (-1) A = -A <\/p>\n\n\n\n
Properties of scalar multiplication<\/strong><\/h4>\n