SOLUTION: How do I go about solving this: "equation of vertical line that contains (-4, 8) its would also be great if you could tell me the general linear form. I have no idea how to begin s

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Question 391197: How do I go about solving this: "equation of vertical line that contains (-4, 8) its would also be great if you could tell me the general linear form. I have no idea how to begin solving this because I do not have the formula. Please and thank you very much.
Found 2 solutions by Edwin McCravy, richard1234:
Answer by Edwin McCravy(20055) About Me  (Show Source):
You can put this solution on YOUR website!
How do I go about solving this: "equation of vertical line that contains
(-4, 8) its would also be great if you could tell me the general linear form. I
have no idea how to begin solving this because I do not have the formula.
Please and thank you very much.
The form is different for vertical lines than for all other lines.  That's
because the slope of vertical lines is undefined.  Vertical lines are
considered to be "infinitely steep". The equation for a vertical line is done
this way:

Here is the given point the vertical line goes through:



Here is the vertical line:



Now let's look at a whole bunch of other points on that line:



Now let's ask the question:  What is true about every one of those points?

Answer:  Every one of them has its x-coordinate as -4.

Therefore the only equation that tells the whole story of that
vertical line is the statement that means:

   " x is always -4 "

and that is the very simple equation:

        x = -4

So that's all there is to the equation of that vertical line.
Every point on a vertical line has its x-value the same.  In
this case it is -4.  So the equation of that green vertical line is
simply: 

        x = -4

There is no solving needed to get the equation of a vertical line.  It's
just x = ___  where you fill a number in the blank which is the x-coordinate
of any point on the line, since they're all the same.

Edwin

Answer by richard1234(7193) About Me  (Show Source):
You can put this solution on YOUR website!
If a linear equation is vertical, then its slope is undefined. The only way for DELTA%28y%29%2FDELTA%28x%29 (the expression for slope) to be undefined is if there is some DELTA%28y%29 such that DELTA%28x%29+=+0. This means that for some change in y, x is held constant. Since the line goes through (-4, 8), then x is held constant at -4. Therefore the equation is x = -4.