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visits member for 2 years, 9 months
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Nov
22
asked What's the meaning of dual concept?
Nov
18
comment How many different ways are there from $(0,0,0)$ to the point $(4,3,5)$?
@ChrisCulter Yes. But as I say, I changed it a bit (and continued afraid of didn't have made my point clearly), then I added the note. In the test, it's not so clear like I wrote.
Nov
18
asked How many different ways are there from $(0,0,0)$ to the point $(4,3,5)$?
Nov
18
accepted Silly mistake on evaluating the sixth term of $\left (\frac{a}{b}+\frac{b}{a^2}\right)^{17}$?
Nov
16
comment Silly mistake on evaluating the sixth term of $\left (\frac{a}{b}+\frac{b}{a^2}\right)^{17}$?
I had evaluated it through the other side and got a different result. Now I see that it's actually that result.
Nov
16
awarded  Great Question
Nov
16
asked Silly mistake on evaluating the sixth term of $\left (\frac{a}{b}+\frac{b}{a^2}\right)^{17}$?
Nov
16
comment Why isn't Mary a victim of the permutation?
John is used in the latter questions. I forgot to take him out of the playground.
Nov
15
asked Why isn't Mary a victim of the permutation?
Nov
15
comment A small doubt about slopes.
@Calculus No need for that. He probably still doesn't know the rules of the place.
Nov
15
comment A small doubt about slopes.
Take for example the function $f(x)=x^2$, the slope of $f(1)$ and of $f(3)$ are different and yet the slope still exists for these points. The slope is uniform for linear functions (eg: $f(x)=x$) but it's not uniform for a lot of other kinds of functions. Perhaps you're confusing it with the idea of existence of the limit.
Nov
15
awarded  Organizer
Nov
15
revised A small doubt about slopes.
edited tags; edited title
Nov
15
comment A small doubt about slopes.
Graph theory is something quite different.
Nov
15
accepted Given the points $A,B,C,D$ in a straight line $m$ and $A,E,F,G$ in a straight line $n$, how many triangles can be formed with these points?
Nov
15
comment Given the points $A,B,C,D$ in a straight line $m$ and $A,E,F,G$ in a straight line $n$, how many triangles can be formed with these points?
@AndréNicolas Oh, sorry. It had one more point, I didn't see it.
Nov
15
comment Given the points $A,B,C,D$ in a straight line $m$ and $A,E,F,G$ in a straight line $n$, how many triangles can be formed with these points?
Yes. The problem is that the answer is $42$.
Nov
15
comment Given the points $A,B,C,D$ in a straight line $m$ and $A,E,F,G$ in a straight line $n$, how many triangles can be formed with these points?
Choosing $A$, I'd have 3 options in $m$ and $3$ options in $n$, so $1*3*3=9$. Now choosing two points in $m$ and one in $n$, I'll have ${3 \choose 2}*3=9$. Now choosing two points in $n$ and one in $m$, I'd have ${3 \choose 2}*3=9$. Hence 9+9+9=27. But this answer is wrong. I don't know what I did wrong.
Nov
15
asked Given the points $A,B,C,D$ in a straight line $m$ and $A,E,F,G$ in a straight line $n$, how many triangles can be formed with these points?
Nov
14
comment Consider the number of $3$ distinct numbers formed with the digits $2,3,5,8,9$. How many of them are even?
@daOnlyBG No. Distinct digits.