Integral-Summation Duality
by Mathandski, Apr 28, 2025, 7:58 PM
Given a continuous function
such that
and
, evaluate
.




Something about (BIC)
by flower417477, Apr 28, 2025, 3:58 PM
Given
with incenter
,
is a point on
,the bisector of
meet
at
.Prove that 








Number of complex solutions (x,y,z)
by CarSa, Apr 27, 2025, 1:18 AM
Find all solutions
to the system of equations
![\[\begin{aligned}
\begin{cases}
x^2+y^2-xy-3x+3=0,\\
x^2+y^2+z^2-xy-yz-2zx-3x+3=0.\\
\end{cases}
\end{aligned}\]](//latex.artofproblemsolving.com/4/a/b/4ab8e94e2e39be219c80264aa5ea23456b74b3e8.png)

![\[\begin{aligned}
\begin{cases}
x^2+y^2-xy-3x+3=0,\\
x^2+y^2+z^2-xy-yz-2zx-3x+3=0.\\
\end{cases}
\end{aligned}\]](http://latex.artofproblemsolving.com/4/a/b/4ab8e94e2e39be219c80264aa5ea23456b74b3e8.png)
This post has been edited 1 time. Last edited by CarSa, Apr 27, 2025, 1:24 AM
Reason: the title was incorrect
Reason: the title was incorrect
Non-negative real variables inequality
by KhuongTrang, Apr 24, 2025, 2:52 PM
A cyclic inequality
by KhuongTrang, Apr 21, 2025, 4:18 PM
Killer NT that nobody solved (also my hardest NT ever created)
by mshtand1, Apr 19, 2025, 9:31 PM
A positive integer number
is chosen. Prove that there exists a prime number that divides infinitely many terms of the sequence
, where
![\[
b_k = a^{k^k} \cdot 2^{2^k - k} + 1.
\]](//latex.artofproblemsolving.com/1/7/5/1751a60482d729a36c71b77ac9c978e724f40da0.png)
Proposed by Arsenii Nikolaev and Mykhailo Shtandenko


![\[
b_k = a^{k^k} \cdot 2^{2^k - k} + 1.
\]](http://latex.artofproblemsolving.com/1/7/5/1751a60482d729a36c71b77ac9c978e724f40da0.png)
Proposed by Arsenii Nikolaev and Mykhailo Shtandenko
Outcome related combinatorics problem
by egxa, Apr 18, 2025, 5:12 PM
A competition consists of
sports, each awarding one gold medal to a winner.
athletes participate, each in all
sports. There are also
experts, each of whom must predict the number of gold medals each athlete will win. In each prediction, the medal counts must be non-negative integers summing to
. An expert is called competent if they correctly guess the number of gold medals for at least one athlete. What is the maximum number
such that the experts can make their predictions so that at least
of them are guaranteed to be competent regardless of the outcome?







This post has been edited 1 time. Last edited by egxa, Apr 18, 2025, 5:21 PM
Infinitely many n with a_n = n mod 2^2010 [USA TST 2010 5]
by MellowMelon, Jul 26, 2010, 4:03 PM
Define the sequence
by
and, for
,
![\[a_n = a_{\lfloor n/2 \rfloor} + a_{\lfloor n/3 \rfloor} + \ldots + a_{\lfloor n/n \rfloor} + 1.\]](//latex.artofproblemsolving.com/a/5/8/a58bbcbb429bcada079bb810b286a7c243f25c41.png)
Prove that there are infinitely many
such that
.



![\[a_n = a_{\lfloor n/2 \rfloor} + a_{\lfloor n/3 \rfloor} + \ldots + a_{\lfloor n/n \rfloor} + 1.\]](http://latex.artofproblemsolving.com/a/5/8/a58bbcbb429bcada079bb810b286a7c243f25c41.png)
Prove that there are infinitely many


Equation Roots
by joml88, Dec 9, 2005, 12:12 AM
The equation
has exactly two real roots, one of which is
where
and
are integers,
and
are relatively prime, and
Find 








"Where wisdom and valor fail, all that remains is faith. . . And it can overcome all." -Toa Mata Tahu
Archives





































































Shouts
Submit
536 shouts
Tags
About Owner
- Posts: 3075
- Joined: Dec 24, 2011
Blog Stats
- Blog created: Jan 14, 2012
- Total entries: 600
- Total visits: 1582144
- Total comments: 771
Search Blog