1
00:00:01,459 --> 00:00:06,399
As a hint, I'll take the determinant of a very similar two by two matrix.

2
00:00:06,399 --> 00:00:10,514
So we wanna figure out the determinant of this matrix and we can denote it

3
00:00:10,514 --> 00:00:13,371
by the determinant of the 2x2 matrix five,

4
00:00:13,371 --> 00:00:17,642
three,negative one and four

5
00:00:17,642 --> 00:00:21,892
and the definition of determinant of the 2x2 matrix like this, as we can first take

6
00:00:21,892 --> 00:00:24,888
this diagonal, five times four

7
00:00:24,888 --> 00:00:29,532
so write it down, just going to be equal to

8
00:00:29,532 --> 00:00:35,777
5 * 4 minus of product of that diagonal

9
00:00:45,792 --> 00:00:46,721
...so what is this

10
00:00:46,721 --> 00:00:50,347
give us? So, five times four is twenty

11
00:00:50,347 --> 00:00:55,362
and then three times negative one will be negative three

12
00:00:55,362 --> 00:00:57,521
this is negative three...

13
00:00:57,521 --> 00:01:01,771
but making negative the negative three will make the positive three

14
00:01:02,969 --> 00:01:08,397
so the determinant of this matrix is twenty three.