Found problems: 3597
1997 Slovenia Team Selection Test, 2
Find all polynomials $p$ with real coefficients such that for all real $x$ , $xp(x)p(1-x)+x^3 +100 \ge 0$.
2006 MOP Homework, 2
Let $a, b_1, b_2, \dots, b_n, c_1, c_2, \dots, c_n$ be real numbers such that \[x^{2n} + ax^{2n - 1} + ax^{2n - 2} + \dots + ax + 1 = \prod_{i = 1}^{n}{(x^2 + b_ix + c_i)}\]
Prove that $c_1 = c_2 = \dots = c_n = 1$.
As a consequence, all complex zeroes of this polynomial must lie on the unit circle.
1984 Spain Mathematical Olympiad, 8
Find the remainder upon division by $x^2-1$ of the determinant
$$\begin{vmatrix}
x^3+3x & 2 & 1 & 0
\\ x^2+5x & 3 & 0 & 2
\\x^4 +x^2+1 & 2 & 1 & 3
\\x^5 +1 & 1 & 2 & 3
\\ \end{vmatrix}$$
2017 NMTC Junior, 2
If $x,y,z,p,q,r$ are real numbers such that \[\frac{1}{x+p}+\frac{1}{y+p}+\frac{1}{z+p}=\frac{1}{p}\]\[\frac{1}{x+q}+\frac{1}{y+q}+\frac{1}{z+q}=\frac{1}{q}\]\[\frac{1}{x+r}+\frac{1}{y+r}+\frac{1}{z+r}=\frac{1}{r}.\]Find the numerical value of $\frac{1}{p}+\frac{1}{q}+\frac{1}{r}$.
2014 NIMO Problems, 3
Let $S = \left\{ 1,2, \dots, 2014 \right\}$. Suppose that \[ \sum_{T \subseteq S} i^{\left\lvert T \right\rvert} = p + qi \] where $p$ and $q$ are integers, $i = \sqrt{-1}$, and the summation runs over all $2^{2014}$ subsets of $S$. Find the remainder when $\left\lvert p\right\rvert + \left\lvert q \right\rvert$ is divided by $1000$. (Here $\left\lvert X \right\rvert$ denotes the number of elements in a set $X$.)
[i]Proposed by David Altizio[/i]
2010 Vietnam Team Selection Test, 3
Let $S_n $ be sum of squares of the coefficient of the polynomial $(1+x)^n$. Prove that $S_{2n} +1$ is not divisible by $3.$
2009 IMO Shortlist, 5
Let $P(x)$ be a non-constant polynomial with integer coefficients. Prove that there is no function $T$ from the set of integers into the set of integers such that the number of integers $x$ with $T^n(x)=x$ is equal to $P(n)$ for every $n\geq 1$, where $T^n$ denotes the $n$-fold application of $T$.
[i]Proposed by Jozsef Pelikan, Hungary[/i]
2012 Indonesia TST, 1
Let $P$ be a polynomial with real coefficients. Find all functions $f : \mathbb{R} \rightarrow \mathbb{R}$ such that there exists a real number $t$ such that
\[f(x+t) - f(x) = P(x)\]
for all $x \in \mathbb{R}$.
1995 Taiwan National Olympiad, 4
Let $m_{1},m_{2},...,m_{n}$ be mutually distinct integers. Prove that there exists a $f(x)\in\mathbb{Z}[x]$ of degree $n$ satisfying the following two conditions:
a)$f(m_{i})=-1\forall i=1,2,...,n$.
b)$f(x)$ is irreducible.
1981 Romania Team Selection Tests, 1.
Consider the polynomial $P(X)=X^{p-1}+X^{p-2}+\ldots+X+1$, where $p>2$ is a prime number. Show that if $n$ is an even number, then the polynomial \[-1+\prod_{k=0}^{n-1} P\left(X^{p^k}\right)\] is divisible by $X^2+1$.
[i]Mircea Becheanu[/i]
2008 AIME Problems, 7
Let $ r$, $ s$, and $ t$ be the three roots of the equation
\[ 8x^3\plus{}1001x\plus{}2008\equal{}0.\]Find $ (r\plus{}s)^3\plus{}(s\plus{}t)^3\plus{}(t\plus{}r)^3$.
2006 Iran MO (3rd Round), 2
Find all real polynomials that \[p(x+p(x))=p(x)+p(p(x))\]
2012 Belarus Team Selection Test, 1
Consider a polynomial $P(x) = \prod^9_{j=1}(x+d_j),$ where $d_1, d_2, \ldots d_9$ are nine distinct integers. Prove that there exists an integer $N,$ such that for all integers $x \geq N$ the number $P(x)$ is divisible by a prime number greater than 20.
[i]Proposed by Luxembourg[/i]
2024 Kyiv City MO Round 1, Problem 4
For a positive integer $n$, does there exist a permutation of all its positive integer divisors $(d_1 , d_2 , \ldots, d_k)$ such that the equation $d_kx^{k-1} + \ldots + d_2x + d_1 = 0$ has a rational root, if:
a) $n = 2024$;
b) $n = 2025$?
[i]Proposed by Mykyta Kharin[/i]
2000 China Team Selection Test, 2
Given positive integers $k, m, n$ such that $1 \leq k \leq m \leq n$. Evaluate
\[\sum^{n}_{i=0} \frac{(-1)^i}{n+k+i} \cdot \frac{(m+n+i)!}{i!(n-i)!(m+i)!}.\]
1978 IMO Longlists, 52
Let $p$ be a prime and $A = \{a_1, \ldots , a_{p-1} \}$ an arbitrary subset of the set of natural numbers such that none of its elements is divisible by $p$. Let us define a mapping $f$ from $\mathcal P(A)$ (the set of all subsets of $A$) to the set $P = \{0, 1, \ldots, p - 1\}$ in the following way:
$(i)$ if $B = \{a_{i_{1}}, \ldots , a_{i_{k}} \} \subset A$ and $\sum_{j=1}^k a_{i_{j}} \equiv n \pmod p$, then $f(B) = n,$
$(ii)$ $f(\emptyset) = 0$, $\emptyset$ being the empty set.
Prove that for each $n \in P$ there exists $B \subset A$ such that $f(B) = n.$
2024 Auckland Mathematical Olympiad, 11
It is known that for quadratic polynomials $P(x)=x^2+ax+b$ and $Q(x)=x^2+cx+d$ the equation $P(Q(x))=Q(P(x))$ does not have real roots. Prove that $b \neq d$.
2005 District Olympiad, 3
a)Let $A,B\in \mathcal{M}_3(\mathbb{R})$ such that $\text{rank}\ A>\text{rank}\ B$. Prove that $\text{rank}\ A^2\ge \text{rank}\ B^2$.
b)Find the non-constant polynomials $f\in \mathbb{R}[X]$ such that $(\forall)A,B\in \mathcal{M}_4(\mathbb{R})$ with $\text{rank}\ A>\text{rank}\ B$, we have $\text{rank}\ f(A)>\text{rank}\ f(B)$.
1999 Putnam, 2
Let $p(x)$ be a polynomial that is nonnegative for all real $x$. Prove that for some $k$, there are polynomials $f_1(x),f_2(x),\ldots,f_k(x)$ such that \[p(x)=\sum_{j=1}^k(f_j(x))^2.\]
2013 Brazil Team Selection Test, 4
Let $f$ and $g$ be two nonzero polynomials with integer coefficients and $\deg f>\deg g$. Suppose that for infinitely many primes $p$ the polynomial $pf+g$ has a rational root. Prove that $f$ has a rational root.
Oliforum Contest III 2012, 2
Show that for every polynomial $f(x)$ with integer coefficients, there exists a integer $C$ such that the set
$\{n \in Z :$ the sum of digits of $f(n)$ is $C\}$ is not finite.
1991 Arnold's Trivium, 91
Find the Jordan normal form of the operator $e^{d/dt}$ in the space of quasi-polynomials $\{e^{\lambda t}p(t)\}$ where the degree of the polynomial $p$ is less than $5$, and of the operator $\text{ad}_A$, $B\mapsto [A, B]$, in the space of $n\times n$ matrices $B$, where $A$ is a diagonal matrix.
1974 Canada National Olympiad, 3
Let \[f(x) = a_{0}+a_{1}x+a_{2}x^{2}+\cdots+a_{n}x^{n}\] be a polynomial with coefficients satisfying the conditions: \[0\le a_{i}\le a_{0},\quad i=1,2,\ldots,n.\] Let $b_{0},b_{1},\ldots,b_{2n}$ be the coefficients of the polynomial
\begin{align*}\left(f(x)\right)^{2}&= \left(a_{0}+a_{1}x+a_{2}x^{2}+\cdots a_{n}x^{n}\right)\\ &= b_{0}+b_{1}x+b_{2}x^{2}+\cdots+b_{2n}x^{2n}. \end{align*}
Prove that $b_{n+1}\le \frac{1}{2}\left(f(1)\right)^{2}$.
2002 AMC 12/AHSME, 25
The nonzero coefficients of a polynomial $P$ with real coefficients are all replaced by their mean to form a polynomial $Q$. Which of the following could be a graph of $y = P(x)$ and $y = Q(x)$ over the interval $-4\leq x \leq 4$?
[asy]//Choice A
size(100);defaultpen(linewidth(0.7)+fontsize(8));
real end=4.5;
draw((-end,0)--(end,0), EndArrow(5));
draw((0,-end)--(0,end), EndArrow(5));
real ticks=0.2, four=3.7, r=0.1;
draw((1,ticks)--(1,-ticks)^^(-1,ticks)--(-1,-ticks)^^(four,ticks)--(four,-ticks)^^(-four,ticks)--(-four,-ticks));
label("$x$", (4,0), N);
label("$y$", (0,4), W);
label("$-4$", (-4,-ticks), S);
label("$-1$", (-1,-ticks), S);
label("$1$", (1,-ticks), S);
label("$4$", (4,-ticks), S);
real f(real x) {
return 0.101562 x^4+0.265625 x^3+0.0546875 x^2-0.109375 x+0.125;
}
real g(real x) {
return 0.0625 x^4+0.0520833 x^3-0.21875 x^2-0.145833 x-2.5;
}
draw(graph(f,-four, four), heavygray);
draw(graph(g,-four, four), black);
clip((-end-r,-end-r)--(-end-r, end+r)--(end+r,end+r)--(end+r, -end-r)--cycle);
label("$\textbf{(A)}$", (-5,4.5));
[/asy]
[asy]//Choice B
size(100);defaultpen(linewidth(0.7)+fontsize(8));
real end=4.5;
draw((-end,0)--(end,0), EndArrow(5));
draw((0,-end)--(0,end), EndArrow(5));
real ticks=0.2, four=3.7, r=0.1;
draw((1,ticks)--(1,-ticks)^^(-1,ticks)--(-1,-ticks)^^(four,ticks)--(four,-ticks)^^(-four,ticks)--(-four,-ticks));
label("$x$", (4,0), N);
label("$y$", (0,4), W);
label("$-4$", (-4,-ticks), S);
label("$-1$", (-1,-ticks), S);
label("$1$", (1,-ticks), S);
label("$4$", (4,-ticks), S);
real f(real x) {
return 0.541667 x^4+0.458333 x^3-0.510417 x^2-0.927083 x-2;
}
real g(real x) {
return -0.791667 x^4-0.208333 x^3-0.177083 x^2-0.260417 x-1;
}
draw(graph(f,-four, four), heavygray);
draw(graph(g,-four, four), black);
clip((-end-r,-end-r)--(-end-r, end+r)--(end+r,end+r)--(end+r, -end-r)--cycle);
label("$\textbf{(B)}$", (-5,4.5));
[/asy]
[asy]//Choice C
size(100);defaultpen(linewidth(0.7)+fontsize(8));
real end=4.5;
draw((-end,0)--(end,0), EndArrow(5));
draw((0,-end)--(0,end), EndArrow(5));
real ticks=0.2, four=3.7, r=0.1;
draw((1,ticks)--(1,-ticks)^^(-1,ticks)--(-1,-ticks)^^(four,ticks)--(four,-ticks)^^(-four,ticks)--(-four,-ticks));
label("$x$", (4,0), N);
label("$y$", (0,4), W);
label("$-4$", (-4,-ticks), S);
label("$-1$", (-1,-ticks), S);
label("$1$", (1,-ticks), S);
label("$4$", (4,-ticks), S);
real f(real x) {
return 0.21875 x^2+0.28125 x+0.5;
}
real g(real x) {
return -0.375 x^2-0.75 x+0.5;
}
draw(graph(f,-four, four), heavygray);
draw(graph(g,-four, four), black);
clip((-end-r,-end-r)--(-end-r, end+r)--(end+r,end+r)--(end+r, -end-r)--cycle);
label("$\textbf{(C)}$", (-5,4.5));
[/asy]
[asy]//Choice D
size(100);defaultpen(linewidth(0.7)+fontsize(8));
real end=4.5;
draw((-end,0)--(end,0), EndArrow(5));
draw((0,-end)--(0,end), EndArrow(5));
real ticks=0.2, four=3.7, r=0.1;
draw((1,ticks)--(1,-ticks)^^(-1,ticks)--(-1,-ticks)^^(four,ticks)--(four,-ticks)^^(-four,ticks)--(-four,-ticks));
label("$x$", (4,0), N);
label("$y$", (0,4), W);
label("$-4$", (-4,-ticks), S);
label("$-1$", (-1,-ticks), S);
label("$1$", (1,-ticks), S);
label("$4$", (4,-ticks), S);
real f(real x) {
return 0.015625 x^5-0.244792 x^3+0.416667 x+0.6875;
}
real g(real x) {
return 0.0284722 x^6-0.340278 x^4+0.874306 x^2-1.5625;
}
real z=3.14;
draw(graph(f,-z, z), heavygray);
draw(graph(g,-z, z), black);
clip((-end-r,-end-r)--(-end-r, end+r)--(end+r,end+r)--(end+r, -end-r)--cycle);
label("$\textbf{(D)}$", (-5,4.5));
[/asy]
[asy]//Choice E
size(100);defaultpen(linewidth(0.7)+fontsize(8));
real end=4.5;
draw((-end,0)--(end,0), EndArrow(5));
draw((0,-end)--(0,end), EndArrow(5));
real ticks=0.2, four=3.7, r=0.1;
draw((1,ticks)--(1,-ticks)^^(-1,ticks)--(-1,-ticks)^^(four,ticks)--(four,-ticks)^^(-four,ticks)--(-four,-ticks));
label("$x$", (4,0), N);
label("$y$", (0,4), W);
label("$-4$", (-4,-ticks), S);
label("$-1$", (-1,-ticks), S);
label("$1$", (1,-ticks), S);
label("$4$", (4,-ticks), S);
real f(real x) {
return 0.026067 x^4-0.0136612 x^3-0.157131 x^2-0.00961796 x+1.21598;
}
real g(real x) {
return -0.166667 x^3+0.125 x^2+0.479167 x-0.375;
}
draw(graph(f,-four, four), heavygray);
draw(graph(g,-four, four), black);
clip((-end-r,-end-r)--(-end-r, end+r)--(end+r,end+r)--(end+r, -end-r)--cycle);
label("$\textbf{(E)}$", (-5,4.5));
[/asy]
2017 CMIMC Team, 10
The polynomial $P(x) = x^3 - 6x - 2$ has three real roots, $\alpha$, $\beta$, and $\gamma$. Depending on the assignment of the roots, there exist two different quadratics $Q$ such that the graph of $y=Q(x)$ pass through the points $(\alpha,\beta)$, $(\beta,\gamma)$, and $(\gamma,\alpha)$. What is the larger of the two values of $Q(1)$?