00:01
Okay, so this question gives us a triangle with these vertices, and it wants us to find the area using a determinant.
00:10
So remember that area is equal to plus or minus one -half to make the sign, whatever we need it to be.
00:21
And in our determinant, we put all of the x coordinates, and then the next column we put their corresponding y values, and then in the third we just put all ones.
00:39
So for our specific example, this means that our area is plus or minus one half times the determinant of list the x values 0, negative 2, 2, then list the corresponding ys.
01:07
And then finally, we just keep a column of once.
01:14
And now we just calculate this determinant and flip the sign if we need to.
01:21
So our area is equal to one half times.
01:29
I'm just dropping the negative sign, and we'll add it back later if we need it...