If [tex]$M=\left[\begin{array}{ll}6 & 8 \\ 5 & 4\end{array}\right]$[/tex], find the value of [tex]$M+M^{\top}$[/tex].



Answer :

To find the value of [tex]\(M + M^\top\)[/tex] where [tex]\(M\)[/tex] is given by

[tex]\[ M = \begin{pmatrix} 6 & 8 \\ 5 & 4 \end{pmatrix}, \][/tex]

we need to follow these steps:

1. Determine the transpose of [tex]\(M\)[/tex]:
The transpose of a matrix, denoted as [tex]\(M^\top\)[/tex], is found by swapping the rows and columns. So, for the given matrix [tex]\(M\)[/tex],

[tex]\[ M^\top = \begin{pmatrix} 6 & 5 \\ 8 & 4 \end{pmatrix}. \][/tex]

2. Add [tex]\(M\)[/tex] and [tex]\(M^\top\)[/tex]:
To add two matrices, we simply add their corresponding elements. Therefore, we have:

[tex]\[ M + M^\top = \begin{pmatrix} 6 & 8 \\ 5 & 4 \end{pmatrix} + \begin{pmatrix} 6 & 5 \\ 8 & 4 \end{pmatrix}. \][/tex]

Now, performing the element-wise addition:

[tex]\[ \begin{pmatrix} 6+6 & 8+5 \\ 5+8 & 4+4 \end{pmatrix} = \begin{pmatrix} 12 & 13 \\ 13 & 8 \end{pmatrix}. \][/tex]

Thus, the resultant matrix [tex]\(M + M^\top\)[/tex] is:

[tex]\[ \begin{pmatrix} 12 & 13 \\ 13 & 8 \end{pmatrix}. \][/tex]