Search found 92 matches

by bristy1588
Wed Feb 01, 2012 12:00 am
Forum: International Mathematical Olympiad (IMO)
Topic: IMO(1995-1) Collinearity Of AM, DN and XY
Replies: 2
Views: 1311

Re: IMO(1995-1) Collinearity Of AM, DN and XY

my solution might be wrong, if it is, i request people to correct it: I have denoted the point $O$ as $P$ here. Sorry for the inconvinience. Let $T$ be the intersection of $AM$ and $XY$(extended). Now $TQ$ is the perpendicualr to $AD$.$Q$ is the foot of perpendicular from $T$ to $AD$. Now, $\angle T...
by bristy1588
Sat Jan 21, 2012 11:19 am
Forum: National Math Olympiad (BdMO)
Topic: BdMO 2010 higher secondary Q. 6
Replies: 7
Views: 2633

Re: BdMO 2010 higher secondary Q. 6

@Nadim,
$a \ne b$ if this condition is maintained, then the ans will be $2.(804)^2 + 401.400$.
by bristy1588
Sat Jan 21, 2012 10:36 am
Forum: National Math Olympiad (BdMO)
Topic: BdMO National Higher Secondary 2010/5
Replies: 3
Views: 1481

Re: BdMO National Higher Secondary 2010/5

I second Nadim ul abrar, I think the answer should be 14.
@Labib.
2010 has 16 divisors out of which there will be no polygons with side 1 or 2, So i think the answer is 14.
by bristy1588
Sat Jan 14, 2012 2:00 pm
Forum: National Math Olympiad (BdMO)
Topic: BdMO National Higher Secondary 2009/6
Replies: 6
Views: 2527

Re: BdMO National Higher Secondary 2009/6

@Labib Rashid: Could you explain your solution again? @Rafi, How did u get 1520?? Well,maybe I am wrong but here is my solution: From 40 movers, 3 movers can be chosen in $\binom{40}{3}$ ways. Now, let us count the number of ways that 3 movers can be selected such that there are no movers who sat ne...
by bristy1588
Sat Jan 14, 2012 1:11 pm
Forum: National Math Olympiad (BdMO)
Topic: BdMO National Higher Secondary 2008/4
Replies: 5
Views: 1721

Re: BdMO National Higher Secondary 2008/4

Tahmid, Tumi ki doye korso bolba??
by bristy1588
Sat Jan 14, 2012 10:42 am
Forum: National Math Olympiad (BdMO)
Topic: BdMO National Higher Secondary 2008/8
Replies: 2
Views: 1281

Re: BdMO National Higher Secondary 2008/8

Is the answer
$18.2$?
by bristy1588
Sat Jan 14, 2012 10:05 am
Forum: National Math Olympiad (BdMO)
Topic: BdMO National Higher Secondary 2008/4
Replies: 5
Views: 1721

Re: BdMO National Higher Secondary 2008/4

TIHAM,

Hint:
Use the following. It might help: :)

1.$\int_{a}^{b}f(g(x))d(g(x))=\int_{g(a)}^{g(b)}f(x)dx$

2.$\frac{d}{dx}(a-x)=-1$

$d(a-x)=-dx$
Answer:
$\frac{1}{2}$
by bristy1588
Wed Jan 11, 2012 4:42 pm
Forum: National Math Olympiad (BdMO)
Topic: BdMO National Higher Secondary 2007/11
Replies: 2
Views: 1218

Re: BdMO National Higher Secondary 2007/11

I did it like this. \[2cosx\leq|\sqrt{1+sin2x}-\sqrt{1-sin2x}|\] by squaring and simplifying 1. \[ 2cos^2x\le 1-cos2x\] 2. \[\Rightarrow 2cos^2x\le2-2cosx\] 3.\[\Rightarrow (cosx+1)(2cosx-1)\le0\] is there any bug :?: Tiham, I did not understand how u got from line 1 to line 2. $cos2x=2cos^2x-1$ Pu...