Hey guys,

i need help with coordinate geometry !!

if anybody could suggest any good books or online tutorials i’d be very glad !!

And could you please also suggest some good problems in co-ordinate geometry to solve ??

coordinate geometry has been a pain in my ass for a long long time just wanna get rid of it by mastering it !!

And also I’d like to know if coordinate geometry is connected with graph theory !!

thanks in advance to all coders !!

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Yes I have problems too in this section… help would be appreciated.

@mecodesta :

Book : Coordinate Geometry by S. L. Loney is an excellent text and very cheap also .

Coordinate geometry is not connected to graph theory in any direct way .

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@mecodesta: Coordinate geometry has been a difficult topic for me too. Handling all those points and lines, finding intersections and areas, and simulating things in euclidean space; these had always been a hassle. Not to mention, the special cases when the line has infinity gradient, or those precision problems that keeps you stuck with RE and WA. Lets say I could easily solve geometry problem on pen and paper, but it was still a challenge to do it elegantly in the code.

Then one day, I realized, things are actually a lot simpler if I just use vector! Trust me, this thing totally changed my perspective. Instead of representing a line as y = mx + c or Ax + By = c, it is much more elegant to represent it as a parametric equation ( P.E ) v = v0 + st.

I first learned about parametric equations in CLRS. It has lots of advantages like, you can easily judge if an intersection between two line segments occurred between the segments or not by the value of t in the parametric equation.

Using P.E I can check if two lines are parallel or not by their cross product. I can check if they are perpendicular or not with dot product. I can rotate a vector 90 degree anti-clockwise with perp product.

Check out this site for more details on vector geometry and code : http://geomalgorithms.com/index.html

Here is a list of problems to solve: https://docs.google.com/spreadsheet/pub?key=0Avbf9q-07MMHdEI4RWhmeXRXQXJNQ09WVWl2TVptalE&output=html

If we can code elegantly, then our lives would be simpler. There are many tricks, formulas and theorems out there that will make things less difficult. We have to continue our search to find them.

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Thats a gr8 doc. Do you have docs for other topics as well?

+1, I remember my 10+2 times. SL Loney’s Trigonometry and Coordinate Geometry, and Hall & Knight’s Higher Algebra

I had one for dp problems in Topcoder. But I lost it. If you are looking for categorized problems with difficulty level, maybe uhunt or ahmed-aly will help.