00:01
For this video, we're going to build the equation of a line that goes through this point, and it will be perpendicular to this equation provided here.
00:10
The first step in this process is to find the slope of this given equation, and the easiest way to do that will be to solve for the y variable.
00:18
So i'm going to add 3 fourths of y to both sides, so we have 3 fourths y plus x equals 5.
00:25
Now subtract x from both sides, so 3 fourths of y, equals negative x, plus 5.
00:33
At this stage if we multiply by four -thirds on the left side and then the right side we will have the y variable salt for so the left side is just y.
00:45
Distributing gives us first negative four -thirds times x then from here to here when we multiply we get 5 by 4 which is 20 thirds.
00:57
What we needed though was a slope m and now that the equation is in slope intercept form, we can read off the slope from the coefficient of x.
01:06
So the slope m is equal to negative four thirds.
01:10
Now let's go back to the information we need to build our line.
01:14
It'll go through this point here and our slope m is going to be such that our line will be perpendicular to the provided line.
01:23
That means we have to have the opposite of this and it's reciprocal three -fourths.
01:29
Now if you were to to take 3 fourths and multiply it by negative 4 thirds, we would get negative 1, and so we know our lines are going to be perpendicular if we use that slope of 3 4ths...