Video Transcript
Given the matrix 𝐴 equals eight, negative three, 11, four, five, negative five, nine, two, negative one, 34, zero, negative seven, which are negative entries of the matrix 𝐴?
So, first of all, what we want to do is identify our negative entries or negative elements of our matrix. So, we can see that in the first row, we have negative three. In our second row, what we have is negative five. And that’s our second element along in the second row. And then, in our third row, what we have is negative one and negative seven. And they’re our first and last elements in the third row.
So now, what we’ve done is identified our negative entries of the matrix 𝐴. However, we need to know how would we represent these? Well, the way that we represent entries is like this. So, for instance, we’d have 𝑎 and then’d we have sub one then two. But what would this mean?
Well, the first number represents the row number and the second number represents the column. So therefore, this would be 𝑎, and then we’d have our entry. And it’d be the entry at row one column two. So what this would actually represent is this entry here, which is negative three, our element. So therefore, this is gonna be our first negative entry. Then, our second negative entry would be 𝑎 sub two two. Then, we’d have 𝑎 sub three one. Then, our final negative entry would be 𝑎 sub three four.
So therefore, we can say that the negative entries of the matrix 𝐴 are 𝑎 sub one two, 𝑎 sub two two, 𝑎 sub three one, and 𝑎 sub three four.
