00:02
All right, here we have a rough sketch of the graph, and we're going to find the equation of each line, and then we'll find out if these lines are perpendicular.
00:11
So line one, i have drawn in blue, and we can see that it goes through the point negative 3 -3 and the point 0.
00:18
So let's use those points to find the slope.
00:21
We could take 3 minus 0, change in y, over negative 3 minus 0, change in x, and that gives us 3 divided by negative 3, which is negative 1.
00:32
We also see the y intercept is zero, so the value of b is zero if we're thinking about the equation y equals mx plus b.
00:40
So let's substitute those numbers in there, and we get the equation, y equals negative 1x plus zero.
00:47
Let's just call that y equals the opposite of x.
00:50
So that's the equation of that line.
00:53
Now let's move on to line two.
00:58
All right, we can do the same kind of thing to find the slope.
01:01
Notice that we know a couple points on the line...