I have a homework problem but I have no idea what to do on it. It says:
Write the equation of the perpendicular bisector of AB: A=(3,8) B=(7,6)

I know that a perpendicular bisector is "The line perpendicular to a segment passing through the segment's midpoint." All I need to know now is how to find it.
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I think white people are better than black people.
While this statement is kinda racist and straightforward, it does have many FACTS to back it up lolz.

Okay, gradient of the line AB;

m = deltaY/deltaX

= -2/4

Sub in (3, 8)

y = mx + c

8 = (-2/4 x 3) + c

6.5 = c

y = -2/4x + 6.5

You now want the opposite line to this, so the gradient becomes 4/2 = 2

[EDITED OUT BECAUSE IT WAS WRONG]

I'm pretty tired right now, so I might have made some stupid mistakes in there.

EDIT: Wait, this could be wrong, I forgot it needs to bisect the two points. Gimme a minute...

Midpoint; (5, 7)

y = 2x + c

7 = 10 + c

c = - 3

y = 2x - 3

*shrug* Like I say, could be wrong in places, but I think it's at least on the right lines.
Co-President of UG's Tubgirl Virgins Club

Last edited by JamieB at Jan 18, 2007,
Find the gradient of the line it bisects. The gradient of the perpendicular bisector is -1/(the gradient of the line it bisects).
Find the midpoint of the line you're given two co-ordinates of.
Put those co-ordinates and the gradient you found into y-y1=m(x-x1) where y1 is the y value of the middle point of the line, and x1 is the x value and m is the gradient.
then re-arrange into either y=mx+c, or whatever form you want.

P.s., if some has already answered, i'm not gonna edit this post and say 'oh crap'
"He remembered that they were but flesh, a passing breeze that does not return"
Alright I worked it out and got y=2x-3
I'm not sure if that's right. I got the midpoint to be (5,7) and the slope to be -2/4 which reduces to -1/2 which ends up being 2 for the perpendicular bisector.
Quote by DaveMustaine08
Quote by puppetmaster917
I think white people are better than black people.
While this statement is kinda racist and straightforward, it does have many FACTS to back it up lolz.

The grad of AB is -1/2 I think, then just do the standard method. I think (5,7) is the mid point. That would mean you get y= 2x - 3? That's all in my head so who knows?
Quote by aixelsydevahi
Alright I worked it out and got y=2x-3
I'm not sure if that's right. I got the midpoint to be (5,7) and the slope to be -2/4 which reduces to -1/2 which ends up being 2 for the perpendicular bisector.

Yes, that'd be right.

I managed to get 6 - 8 = -1

Now I've corrected it and I get the same as you.
Co-President of UG's Tubgirl Virgins Club

Alright great. Thanks for all the help
Quote by DaveMustaine08
Quote by puppetmaster917
I think white people are better than black people.
While this statement is kinda racist and straightforward, it does have many FACTS to back it up lolz.

Quote by aixelsydevahi
Alright great. Thanks for all the help

You did it all yourself.
Co-President of UG's Tubgirl Virgins Club

Quote by JamieB
You did it all yourself.

no he didn't!
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no he didn't!

Yes he did!
Co-President of UG's Tubgirl Virgins Club

Quote by JamieB
Yes he did!

why did he say, thanks for the help, you cheater helper!
Yes, I know it's been answered, BUT I'm still on break, and typing these things up in paint is a nice break from reading.

That said, enjoy my educational picture.

I saved that for future use.
Quote by DaveMustaine08
Quote by puppetmaster917
I think white people are better than black people.
While this statement is kinda racist and straightforward, it does have many FACTS to back it up lolz.

It's perpendicular, not parallel
Co-President of UG's Tubgirl Virgins Club