Search found 66 matches

by shehab ahmed
Fri Jun 15, 2012 8:32 pm
Forum: Algebra
Topic: FE
Replies: 0
Views: 669

FE

Find all functions $f:\mathbb R \mapsto \mathbb R$ such that $f(f(x+y))=f(x+y) +f(x)f(y) - xy$
by shehab ahmed
Tue Jun 12, 2012 10:07 pm
Forum: Algebra
Topic: Flooring Square-Roots
Replies: 3
Views: 1289

Re: Flooring Square-Roots

Hint:
you can suppose that n=a^2 + b where 0<b<2a+1 and consider some other cases
by shehab ahmed
Sun Jun 10, 2012 10:00 pm
Forum: Algebra
Topic: F.E.(4)
Replies: 5
Views: 1445

Re: F.E.(4)

Oops,sorry.I didn't notice the '|' sign at first sight from my mobile
by shehab ahmed
Sun Jun 10, 2012 9:57 pm
Forum: Number Theory
Topic: perfect square,perfect brainteaser
Replies: 4
Views: 1677

Re: perfect square,perfect brainteaser

2*8*9 is a perfect square but (2,8,9)=1
by shehab ahmed
Sun Jun 10, 2012 8:29 pm
Forum: Algebra
Topic: F.E.(4)
Replies: 5
Views: 1445

Re: F.E.(4)

Please,post the question carefully
by shehab ahmed
Wed May 30, 2012 12:18 pm
Forum: Geometry
Topic: IMO 2000
Replies: 1
Views: 905

IMO 2000

Two circles x and y intersect at M and N.Let l be the common tangent to x and y such that M is closer to l than N is.Let l touch x at A and y at B.Let the line through M parallel to l meet the circle x again at C and the circle y again at D.Lines CA and DB meet at E,lines AN and CD meet at P,lines B...
by shehab ahmed
Tue May 29, 2012 12:49 pm
Forum: Number Theory
Topic: finding reduced residue system
Replies: 11
Views: 3590

Re: finding reduced residue system

ল্যাটেক্স করে দেয়ার জন্য ধন্যবাদ।মোবাইল থেকে LATEX ব্যবহার করা বহুত পেইন।একেকটা চিহ্ন লিখতে দিয়ে দরকারি কয়েকটা কাজ করে এসে দেখব তখনও ওয়েটিং চলতাসে।
by shehab ahmed
Mon May 28, 2012 10:56 pm
Forum: Number Theory
Topic: finding reduced residue system
Replies: 11
Views: 3590

Re: finding reduced residue system

আমার সলিউশনটা কেউ দেখ।আমি শিওর এখানে কোথাও না কোথাও ভুল আছে first let, $(n,\varphi (m))=1$ and $p$ be any prime factor of $m$ and $p^a||m$ we are given that all $a_i$'s are incongruent and co-prime to $m$. Now,for sake of argument, let $a_i^n$ and $a_j^n$ are congruemt modulo $m$ that is modulo $p^a...
by shehab ahmed
Mon May 28, 2012 12:26 am
Forum: National Math Camp
Topic: IRAN 1995
Replies: 1
Views: 1542

IRAN 1995

Let,the in-circle of $\Delta ABC$ touches the sides of the triangle at $D,E,F$. Let $X,Y,Z$ be the midpoints of $DE,EF,FD$.Prove that the line joining the circum-centre of $\Delta XYZ$ and the circum-centre of $\Delta ABC$ goes through the in-centre of $\Delta ABC$.
by shehab ahmed
Sat May 26, 2012 8:26 pm
Forum: Number Theory
Topic: finding reduced residue system
Replies: 11
Views: 3590

Re: finding reduced residue system

what is the meaning of reduced residue system?i don't know