1971 Canadian MO Problems

Revision as of 21:47, 13 December 2011 by Airplanes1 (talk | contribs) (Problem 6)

This is an empty template page which needs to be filled. You can help us out by finding the needed content and editing it in. Thanks.

Problem 1

$DEB$ is a chord of a circle such that $DE=3$ and $EB=5 .$ Let $O$ be the center of the circle. Join $OE$ and extend $OE$ to cut the circle at $C.$ Given $EC=1,$ find the radius of the circle

CanadianMO 1971-1.jpg


Solution

Problem 2

Let $x$ and $y$ be positive real numbers such that $x+y=1$. Show that $\left(1+\frac{1}{x}\right)\left(1+\frac{1}{y}\right)\ge 9$.

Solution

Problem 3

$ABCD$ is a quadrilateral with $AD=BC$. If $\angle ADC$ is greater than $\angle BCD$, prove that $AC>BD$.

Solution

Problem 4

Determine all real numbers $a$ such that the two polynomials $x^2+ax+1$ and $x^2+x+a$ have at least one root in common.


Solution

Problem 5

Solution

Problem 6

Show that, for all integers $n$, $n^2+2n+12$ is not a multiple of 121. Solution

Problem 7

Solution

Problem 8

Solution

Problem 9

Solution

Problem 10

Solution

Resources