Proofs+and+Question

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** What is the minimum number of dots needed to form //n// lines, if n=/>1, and a line passes through exactly two dots, and a point of intersection is not counted as a dot? ** ======

[|PowerPoint 27th August 2011.pptx]~Ryan Wee. Here is the PowerPoint. It is different from the one I uploaded at about 2 p.m. The script is below. I think that the proof here is also different and better than the previous one. [|Script so far for the PowerPoint 27-8-2011.docx]~Ryan Wee. Here is the scrirpt. I think that the proof here is also different and better than the previous one

~Sorry, the first draft was wrong. Here is the second draft! Ryan Wee.

The first draft of the proof by Ryan Wee: (but **my formula is a sequence**, I need to change it, can someone help me? I think that I need to use the **triangle number formula** - **//n(n+1)/2//** Thank you! ~Ryan Wee