00:01
If you want an equation of a line that has undefined slope.
00:06
So if we're talking about a horizontal line that has a slope of zero, and then a vertical line has undefined slope, vertical line.
00:17
So if we're talking about undefined slope, and it has to have a point negative 8, 5, so you go back 8 and then up 5, be right about in there.
00:33
But it has to be a vertical line.
00:35
It would be a vertical line.
00:43
Okay.
00:44
So it includes that point right there.
00:47
That point is negative 8, 5, and it's vertical.
00:51
All vertical lines would be, are just plainly x equals horizontal lines.
00:59
Like if i had a horizontal line that was going this way, it would be labeled.
01:04
It'd be named y equals whatever that number is.
01:07
That hits the y axis right there.
01:09
In our case, we're hitting the x axis at negative 8.
01:12
So x equals negative 8 is the equation for this line.
01:16
That's it.
01:16
That's all you can do.
01:21
So check that the ordered pair that represents the given point satisfies this equation.
01:27
Yeah, x equals negative 8.
01:30
Part 2.
01:36
Okay, so there's our equation for part 1.
01:38
Part 2, find an equation of a line that contains a given point and is parallel.
01:44
And it has to be parallel to this equation right here.
01:52
Lines that are parallel have the same slope.
01:55
Lines that are parallel have the same slope.
01:57
So if i take 2x minus 3 .3 ,000.
02:00
3y equals negative 24 and i solve for y.
02:06
So move the 2x over, divide by negative 3.
02:19
Y equals positive 2 thirds x plus 8.
02:26
So the number in front of x is the slope.
02:29
So i have a line.
02:31
I want to make a line that has a slope of 2 thirds.
02:37
I have to have the same.
02:38
It's got to have the same slope because it's parallel.
02:41
And it has to go through negative.
02:43
4, 7.
02:44
It must contain negative 4, negative 7.
02:49
So i need a y equals 2 thirds x plus b.
02:58
That number i hear at the end is the y intercept.
03:01
So i need to figure out what my y intercept is going to be to go through this right here.
03:07
So i take my point and i plug it back in and now i can solve for my b value.
03:20
So all i did was take my negative 7, put it in for y, took a negative 4, put it in for x now i'm going to solve for b figure out what my my y intercept is so that would be negative negative 7 equals negative 8 thirds which is multiply the top number here plus b and now we're going to we're going to add this away okay so if i'm going to add this without a calculator 7 is like saying negative 21 thirds i multiply the 7 times 3 to get the top number here here and i'm going to add that 8 to it.
04:07
Negative 21 plus 8...