\input amstex
\input cyracc.def
\font\tencyr=wncyr10
\def\cyr#1{{\tencyr\cyracc#1}}
\def\sgn{\,\mathrm{sgn}\,}

\noindent
\cyr{1) Dokazati da je }$\Phi$\cyr{ slichnost:}

$$\Phi:\cases
x'&=-4x-8y+z+14,\cr
y'&=4x-y+8z+6,\cr
z'&=7x-4y-4z-8,\cr
\endcases$$

\noindent
\cyr{2) Odrediti osnovne komponente.}

\noindent
\cyr{3) Skicirati putanju tachke.}
\bye