## Search found 550 matches

- Thu Sep 25, 2014 11:14 pm
- Forum: Algebra
- Topic: Another Tricky FE
- Replies:
**3** - Views:
**1468**

### Re: Another Tricky FE

Solution: Let $f(x)=x^{3}+g(x) \forall x\in \mathbb{R}$. Now the given statement can be written as $(x-y)(x+y)^{3}+(x-y)g(x+y)-(x+y)(x-y)^{3}-(x+y)g(x-y)=4xy(x^{2}-y^{2})$. Simplification yields $(x-y)g(x+y)=(x+y)g(x-y)$. Let us denote the last statement by $Q(x,y)$. Then $Q(x+1,x)\Rightarrow g(2x+1...

- Mon Sep 15, 2014 10:07 pm
- Forum: Number Theory
- Topic: Infinintely many squares of a form
- Replies:
**7** - Views:
**2509**

### Re: Infinintely many squares of a form

What if we are asked to find all ordered $(a,b)$ such that $(a^2+b^2+3ab)$ is a perfect square?Does there exist infinite many pairs $(m,n)$ of positive integers such that $(a^2+b^2+3ab)$ is a perfect square?

- Tue Aug 26, 2014 11:04 pm
- Forum: Number Theory
- Topic: F.E (Canada-2002)
- Replies:
**2** - Views:
**979**

### Re: F.E (Canada-2002)

Let us denote the statement $mf(n)+nf(m)=(m+n)f(m^{2}+n^{2})$ by $P(m,n)$. Then, $P(0,n)\Rightarrow nf(0)=nf(n^{2})$. So $f(n^{2})=f(0) \forall n\in\mathbb{N}_{0}$. Now let $n_{0}$ be any non-negative integer. Let us take $m_{0}$ such that $(m_{0},n_{0})=1$. Then clearly $(n_{0},m_{0}^{2}+n_{0})=1$....

- Sun Aug 24, 2014 12:09 am
- Forum: International Mathematical Olympiad (IMO)
- Topic: IMO 2014 - Day 1 Problem 3
- Replies:
**2** - Views:
**1723**

### Re: IMO 2014 - Day 1 Problem 3

In my solution the reflections of $C$ wrt $B,D$ are $C_1,C_2$ respectively. I also proved that $C_1$ is the isogonal conjugate of $T$ wrt $\triangle ASH$ in the same way Asif did. Thus it is easy to see that $\angle TSH=\angle C_1SB$. Now, $\angle AHT=\angle C_1HS=\angle C_1CS=\angle BC_1S=90^{\circ...

- Mon Feb 10, 2014 6:10 pm
- Forum: Junior Level
- Topic: Last goes first
- Replies:
**3** - Views:
**1574**

### Re: Last goes first

@Fatin:

It is easier to solve the equation, $10a+2=3\times (200000+a)$.

It is easier to solve the equation, $10a+2=3\times (200000+a)$.

- Thu Feb 06, 2014 6:09 pm
- Forum: Combinatorics
- Topic: rotating a colored square
- Replies:
**5** - Views:
**2621**

### Re: rotating a colored square

the question said $90^{\circ}$.asif e elahi wrote:How many times is the square rotated ?

- Tue Feb 04, 2014 6:21 pm
- Forum: National Math Olympiad (BdMO)
- Topic: BdMO National Secondary 2011/10
- Replies:
**7** - Views:
**2962**

### Re: BdMO National Secondary 2011/10

I have done this: Clearly we have to find $n$ such that $10^{n}+1$ is not square free, and we know $10^{11}+1$ is one (Thanks to Masum vai and LTE). Now $\displaystyle\frac{100000000001}{11^{2}}=826446281$. Let us take $a=82644628100=826446281\times 10^{2}$. Then the repetition of $a$,an $11$ digit ...

- Sun Feb 02, 2014 9:57 pm
- Forum: National Math Olympiad (BdMO)
- Topic: BdMO National 2013: Higher Secondary 4
- Replies:
**5** - Views:
**2907**

### Re: BdMO National 2013: Higher Secondary 4

I got $\frac{11}{6}$. Is it the answer?

- Wed Jan 29, 2014 7:45 pm
- Forum: National Math Olympiad (BdMO)
- Topic: BdMO National 2013: Higher Secondary 4
- Replies:
**5** - Views:
**2907**

### Re: BdMO National 2013: Higher Secondary 4

Is it enough to find the successor term of $\frac{14}{17}$ in fairy sequence $f_{17}$?

- Sun Jan 26, 2014 6:58 pm
- Forum: National Math Olympiad (BdMO)
- Topic: BdMO National 2012: Secondary 9
- Replies:
**6** - Views:
**2708**

### Re: BdMO National 2012: Secondary 9

(I am posting this via a friend of mine) Let us colour the points which are chosen. Now call a point "Row happy" if it is the only coloured point in its row. Similarly define "Column happy" points. Now by the pigeon-hole principal, at least one of the rows contain more than $1$ point. So the number ...