这道题目哪位帮我看看

WalkByFaith

哪位能帮我解释一下，谢谢

The maximum possible                   

 number of lines determined                   n ( n -1) / 2

by n points ( n > 1)

 

 

是求n个点所决定的最大直线数目，这个式子怎么列呢？

fhhrewr

What's the full question?  This doesn't make sense...  n*(n-1)/2 is a quadratic equation that gives you a parabola...

WalkByFaith

but this is the entire question on a GMAT refernces ,therefore, I put it on BBS for answer

forwardxu

两点确定一条直线,所以最大直线数为C(n,2)= n ( n -1) / 2 , so the answer is obvious.

teyvhf

two dots make a line. equals to C^{2_{n = n(n-1)/2}}