Question

grrrrr! find the exact difference between the two lines:
y=2x+2
4x-2y=8 HOW????? please help!

Answer 1

What do you mean by 'exact difference?'

Answer 2

the exact distance, i think is what my teachr ment

Answer 3

The lines aren't parallel, so there isn't a single constant distance between them.

Answer 4

Oh, wait, maybe they are parallel . . .

Answer 5

they have the same slopes though, which makes them parallel, i just cant find distance

Answer 6

do you know to fin distance?

Answer 7

Gah, that's it, I'm putting my glasses on. I'm missing minus signs tonight everywhere...

Answer 8

One way is to find the length of a line segment perpendicular to both of those lines.

Answer 9

how do i do that????

Answer 10

There's a formal, analytic way of doing it, but it might make more sense to look at a graph of the lines and see what that perpendicular line should look like.

Answer 11

You should also remember that a line is perpendicular if it has opposite-reciprocal slope, so if the slope of one line is m=2, the slope of the perpendicular is -1/2.

Answer 12

but from there, how do i find distance??

Answer 13

"Gah, that's it, I'm putting my glasses on. I'm missing minus signs tonight everywhere..." :D

Answer 14

You can pick any point you want on the first line; I'd take (0,2) 'cause the numbers are nice and small.
Then starting from there, draw a line perpendicular (remember, with a slope of -1/2) to the other line and see where it intersects.

Answer 15

If you can't see exactly where they intersect, you can solve for the point by setting the two lines equal to each other (the second parallel line and the new perpendicular line, that is).

Once you have those two end-points of the perpendicular, you can use distance formula (i.e. Pythatgorean Theorem).

Answer 16

k, im gonna try and draw this and you could critique it?

Answer 17

Sure.
In the meantime, I'm going to try to remember the short-cut . . .

Answer 18

it is crappy but they are suppose to parallel, am i right??