1. page 12 problem 33: replace "100" by "99"
2. page 126 line 3: replace "f(U)\subset V" by "f(U)\backslash\{x_0\})\subset
V"
3. Page 303 line 15: replace the display by
1\leq c_0\leq b_1< c_1< b_2< \cdots < b_i
4. Page 303 line 17: replace "E\subset A" by "E=A\cap (\{1,2,\ldots, n\}\backslash
\{c_0,b_1,c_1,b_2,\ldots, b_m,c_m\})"
5. Page 405 line 9 from the bottom: repalce "\mbox{Re}(-a_2z^{-2}-\cdots -a_nz^{-n})" by
"\mbox{Re}(-a_{n-2}z^{-2}-\cdots -a_0z^{-n})"
6. Page 406 line 8 from the bottom: add
"\leq 9(|z|^{-2}+|z|^{-3}+\cdots +|z|^{-n})"
at the begining of the line in the second line of the display.
7. Page 263 line 5: replace "4^1+1^2" by "4^1+1^2+1"
(add a 1)
8. Page 324 line 21: replace "S_n" by "S_9"
9. page 294 problem 856: replace the second occurence of the word "edges" by
"vertices"
10. page 292 first line: after "complete graph" add " with $R(p,q)$ vertices"
11. page 515 line 15: insert "Mathematical" between "Romanian" and "Olympiad"
12. page 68 line 5 from the bottom: replace "positive" by "nonnegative"
13. page 79 line 4 from the bottom: delete the comma between "mechanics" and
"observable"
14. page 296 line 4 from the bottom: insert "of" between "and" and "the
position"
15. page 312 line 10: delete the word "combinatorial"
16. page 132 line 15: - delete the bar over z in $\psi(z)=f(z)-f(-\bar{z})$
- on next line, delete the entire content of the paranthesis; the phrase
should end with the word "continuous"
- on next line delete the bar over z_0
- in the display, delete the two bars over z_0
To conclude, in the entire paragraph there should be no bars.
17. page 148 lines 8 and 6 from the bottom: to be very rigorous, the argument
of the natural logarithm in the two displays should be taken in absolute
value. So we should have "\ln |\sin x+\cos x|" instead of
"\ln (\sin x+\cos x)", three times.
18. page 103 line 9: the two exponents in the general term formula should both
be $n$, not $m$.
19. Replace the first example from section 2.2.3. page 52 with
the following:
\bes
20. Page 718 line 1: 7^z should be 7^zx
21. On the cover there is a repeated "to" on the last line.
22. Page 7 line 1: add "a" before $1\times 1$.
23. Page 93 line 21: in the statement of problem 286 it would look much better
if instead of "$(\sin n)_n$" there was "$(\sin n)_{n\geq 1}$"
24. Page 183 last line: replace {\bf i} {\bf j} {\bf k} by \vec{i} \vec{j}
\vec{k}
25. Page 102 line 9: replace "$\lambda _{1,2}=\frac{1\pm \sqrt{5}}{2}$" by
"$\lambda _1=\frac{1-\sqrt{5}}{2}$ and $\lambda_2=\frac{1+\sqrt{5}}{2}$"
26. Page 206 line 11: "Let $ABC$ be a convex quadrilateral" should be "Let
$ABCD$ be a convex quadrilateral"
27. Page 254 line 15: put ( ) around f(2n+1) and f(2n) so that they look like
(f(2n+1))^2-(f(2n))^2
28. Page 585 line 11: insert "not" between "is" and "identically"
29. Page 684 line 13: "\lfloor x_1+\frac{1}{2}\rfloor" should read "\lfloor nx_1+\frac{1}{2}\rfloor"
an n is missing
30. Page 185 line 4 from the bottom: the third term in the equation should be
"\frac{(x+f(0))^2-(x-y)^2-(f(0))^2+y^2}{2x}"
31. Page 112 line 4 from the bottom: replace "\frac{1}{2}(x+1)" and $2(x+1)$ by $\frac{1}{2}(x+2)"
and "2(x+2)"
32. Page 112 line 2 from the bottom : replace "x\cdot \frac{x+1}{2}" by "x\cdot \frac{x+2}{2}"
and "2x(x+1)" by "2x(x+2)"
33. Page 331 line 7: Delete the sentence that starts with "We assume in" and
ends with "problem."
34. Page 610 line 4 from the bottom: the vertical bars around the cross product of OM and OP should
be doubled, therefore they should be \| and \|
35. Page 610 line 1 from the bottom: in the bracket, the \times between AE and
AC should be +
36. Page 199 delete lines 13 and 14, namely delete the sentence that starts
with "An alternative approach..."
37. Page 730 line 4 from the bottom: delete the comma between $r-1$ and
transpositions.
38. Page 547 line 4 from the bottom: it should be $f'(x)\geq f'(1)$
39. Page 159 line 13: replace $f'(0)>0$ by $f'(1)>0$.
40. The solution to problem 818 at page 279 is wrong and cannot be fixed.
Here is a possible replacement:
Solution (to be replaced at page 722, line 4):
41. Page 304 problem 882: in the first sum, the summation
should be from "i=0" instead of "j=0"
42. Page 761 line 12: $\{0,1\}^n$ should be $\{0,1\}^{p+q+1}$.
43. Page 760 line 9: the expression in the display should be
$\sum_{k=0}^m{m\choose k}{{n+k}\choose m}$. The expression written
there has nothing to do with the problem.
44. Page 30 line 13: in the display there should be $(n-1)^2$
instead of $(n^2-1)^2$.
45. Page 41: problem 122 is silly, it should be ignored.
46. Page 268 line 2 from the bottom: the $a_n$ in $x\equiv a_n$
should be $a_k$.
47. Page 269 line 8: Warsawa should read Warszawa.
48. Page 711 line 7 from the bottom: Warsawa should read Warszawa.
49. Page 132 in the solution to the example, all the bars over z and z_0
should be ignored (there are 5 of them). As such, "$-z$ is diametrically
opposite to $z$".
50. Page 480 the third display: the "+4" in the denominator should
be a "+2".
\begin{example}
Find all cubic polynomials $P(x)$ with the property
that $P(x)$ is a multiple of $P''(x)$.
\end{example}
Set $P(x)=Q(x)P''(x)$, with $Q(x)$ a quadratic polynomial.
Differentiation twice this relation we obtain
\begin{eqnarray*}
P''(x)=Q''(x)P''(x)+Q'(x)P'''(x).
\end{eqnarray*}
Hence $P''(x)(1-Q''(x))=Q'(x)P'''(x)$. We deduce that
$P'(x)$ is a constant multiple of $Q'(x)$. Incorporating the
constant into $Q(x)$, we see that $P(x)=Q(x)Q'(x)$ for
some quadratic polynomial $Q(x)$. It is not hard
to check that each polynomial of this form has the
desired property.
\ens
Find all positive integers $x,y$ such that $15^x-6^y=9$.
Clearly $x=y=1$ is a solution, while $y=2$ does not yield a solution. If $y>2$, then reducing
modulo $4$ we obtain that $x$ is even, $x=2n$. The equation can be rewritten as
$15^{2n}-9=6^y$ or
\begin{eqnarray*}
9(5^n\cdot 3^{n-1}+1)(5^n\cdot 3^{n-1}-1)=2^y\cdot 3^y.
\end{eqnarray*}
Because $y>2$, the left-hand side should have an additional factor of $3$. This can
only happen when $n=1$, so the only other solution to the given Diophantine equation
is $x=2,y=3$.