00:01
So our goal on this example is to write the equation in slope intercept form that passes to the given point and is perpendicular to the given line.
00:09
So that's my blue line.
00:10
I've used two different colors on purpose to really show that there are two different lines happening.
00:17
Ultimately, my goal is to do slope intercept form that passes to the given point.
00:21
So that's red.
00:23
So if i could set up my answer right now, it would be down here and it would be all in red.
00:27
Y equals mx plus b and that's slope intercept form.
00:30
Now to have a slope intercept equation, i need a slope and a y intercept.
00:35
Here's my red information, and that's not a slope or a y intercept.
00:38
It's an x and a y coordinate.
00:40
But i am told that it's perpendicular to my given line.
00:45
So that's my blue line.
00:47
The reason that's important to know that they're perpendicular is because perpendicular lines have a special relationship with their slopes.
00:53
Their slopes are opposites and reciprocals.
00:56
So if i know the slope of my blue line, then i would be able to figure out the slope of my red line.
01:03
So let's see if i can find the slope of my blue line.
01:05
To look at an equation and know its slope right away, y should be isolated.
01:09
It should be in slope intercept form, because then once y is isolated, your slope is your coefficient of x.
01:14
In this case, y is not isolated.
01:16
So i'm going to go ahead and do that.
01:17
So to do that, i would add 8.
01:19
Then i have to do on the other side...