00:01
Okay, so in this question we're asked to draw picture of a line and a vector.
00:05
And essentially we want the line that passes through the point to 1 and is perpendicular to the vector i plus 2j.
00:13
And we're given this sort of fact in here to work with that the vector a i plus bj, right? it's perpendicular to the line a x plus b y equals c for any c here.
00:25
All right.
00:27
So using the fact, so using the fact, we know that our line that we want to find for it to be perpendicular to i plus 2j, this is 1i plus 2j, it means that the line will be of the form x plus 2y equals c for some c in r.
00:49
The reason for this is big, the fact is this one, right? we're just using the fact that a x plus b y equals c is perpendicular to this vector right so this gives us part of the equation of the line and then c must be obtained by substituting at the point so using the point p we can include that c is equal to x x is 2 plus 2 times 1 which is 4 right so the line has equation x plus 2 y equals 4 okay, and now let's make a picture of both these things.
01:29
So let's start with the vector.
01:30
So let's do one, two, three, four in here.
01:33
One, two, three, four.
01:36
All right, and let's see.
01:39
First, the vector.
01:40
So i'm going to draw the vector in red, right? like this...