Co-ordinate Geometry Formulae

Piste

Well I sit down to study for tomorrow's impending doom, and what do I notice? That none of my carefully taken(!) notes include the formuale for co-ordinate geometry. So I'd really appreciate if someone could post the formulae we need to know for distance, midpoint, slope of a line etc.

Thanks

BMH

Lazy smhuch.

Distance=[Square root of](x2-x1)+(y2-y1)
Slope= y=(slope)x+c OR y2-y1/x2-x1
Midpoint= (x1+x2/2, y1+y2/2
Intersections can be found using simultaneus equations
Parallel lines have equal slopes
Lines perpindicular to each other have slopes that multiply to make -1. To find the slope of a line that is perpindicular to a line that you have the slope of, turn the fraction up-sidedown and change the sign, eg, 1/1 => -1/1; 2/3 =>-3/2

Piste

Lazy eh?! I got up off my ass to post here! call that lazy?!

But thank you for your help

disney

You forgot equatation of a line
y-y1=m(x-x1)

Now wudnt u be kickin urself tomorrow if that came up, and I didnt tell ya!!!;)

Piste

Thank you for that Disney

disney

Good Luck 2 Ya 2mrw!!!

Piste

And to you too

PurpleFistMixer

I edited the thread title because the typo was irritating me.

modular

BMH wrote:

Distance=[Square root of](x2-x1)+(y2-y1)

Not sure if I'm too late getting to this one, but each bracket in this formula is supposed to be squared.

Distance = [square root of] (x2-x1)^2 + (y2-y1)^2.

Hopefully you'll see this in time. Good luck on the exam.