\documentclass[a4paper,10pt]{article}
\usepackage[T1]{fontenc}
\usepackage[polish]{babel}
\usepackage{amsfonts}
\fontencoding{T1}
\usepackage[utf8]{inputenc}
\addtolength{\textwidth}{2cm}
\addtolength{\textheight}{1cm}


\begin{document}
\abovedisplayskip=4pt plus 2pt minus 2pt 
\belowdisplayskip=4pt plus 2pt minus 3pt

\def\ss{\vskip10truept}

%\baselineskip=.205in

\def\prefoot{{\it Lista 3}}
\def\postfoot{{\it Strony 5-6}}


\font\smr=plr7 scaled\magstep0
\font\hsmr=plr9 scaled\magstep0
\font\srm=plr7 scaled\magstep0
\font\sc=plcsc10 scaled\magstep1
\font\ssrm=plr5 scaled\magstep0

\long\def\rozw#1{}
\long\def\odp#1{}
\def\coto{Zadania}

\def\N{\mathbb{N}}
\def\ln {{\hbox{ln}}}
\def\log {{\hbox{log}}}
\def\sln {{\hbox{\srm ln}}}
\def\slog {{\hbox{\srm log}}}
\def\arctg {{\hbox{arctg}}}
\def\ssln {{\hbox{\ssrm ln}}}
\def\sarctg {{\hbox{\srm arctg}}}
\def\sgn {{\hbox{sgn}}}
\def\fora{\mathop{\forall}}
\def\exi{\mathop{\exists}}
\def\maps{\longrightarrow}
\def\imply{\Rightarrow}

\def\klepsydra#1{\vbox{\hrule\vtop{\hbox{\vrule
\strut\thinspace#1\thinspace\vrule}\hrule}}}

\def\lub#1#2{\hskip0.0truept\klepsydra{#1}\klepsydra{#2}\hskip3.8truept}
\def\luub#1#2{\par\klepsydra{#1}\par\klepsydra{#2}}


\def\sss{\vskip 14truept}

\newcount\nu
\def\nn {{\vskip 8.7truept \bf \the\nu .\   \global\advance\nu by 1}}
\def\nx {{\hskip 10truept \bf \the\nu .\   \global\advance\nu by 1}}
\def\ny {{\vskip2truept\noindent \bf \the\nu .\   \global\advance\nu by 1}}
\def\nz {{\hskip -2truept
\bf \the\nu .\   \global\advance\nu by 1}}

\nu=76
\setcounter{page}{7}
{\centerline{\large \bf Powtórzenie I.}}

\ss

%\noindent{\small Wykład: zad. 1-4\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 
%\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 
%Konwersatorium 8.10.2009: zad. 38-40}

\noindent{\small Ćwiczenia tydzień 5: zad. 116-139\ \ \ \ 
Kolokwium nr \#, 05.04.2010: Lany Poniedziałek - nie ma zajęć}


\sss


{\bf Zadania powinny być rozwiązane na tablicy przez studentów w celu uzyskania punktów za aktywność}

\ss

\nn Udowodnij, że $n^3\le 3^n$ dla $n\in\Bbb N$.

\nn Oblicz
$$\sum_{k=1}^n k^2$$
{\bf Wskazówka:} $\sum_{k=1}^{n+1} k^3=\sum_{k=0}^{n} (k+1)^3$







\end{document}





