Answer: Option 3
Step-by-step explanation:
A matrix is diagonal if

In other words, you want non-zero elements only when the indices of the row and the column are the same: the first element of the first row must be non zero, the second element of the second row must be non-zero, and so on. All other elements must be zero.
The slope of a line that is perpendicular to the line y = 8x + 5 will be -1/8.
<h3>What is the slope of perpendicular lines?</h3>
Suppose that first straight line has slope 's'
Let another straight line be perpendicular to this first line.
Let its slope be 'a'
Then due to them being perpendicular, they have their slopes' multiplication as -1
or
s x a = -1
s = -1/ a
Slope of line y = 8x + 5
s = 8
The slope of a line that is perpendicular to the line y = 8x + 5
8 x a = -1
a = -1/8
Thus, the slope is -1/8.
Learn more about slope here:
brainly.com/question/2503591
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