[latex]tgalpha= frac{4}{3}\ frac{sinalpha}{cosalpha}= frac{4}{3}\ 3sinalpha= 4cosalpha\ sinalpha= frac{4}{3}cosalpha\ sin^2alpha+cos^2alpha=1\ (frac{4}{3}cosalpha)^2+cos^alpha=1\ frac{16}{9}cos^2alpha+cos^2alpha=1\ frac{25}{9}cos^2alpha=1\ cosalpha= frac{3}{5} lub cosalpha= -frac{3}{5}[/latex] [latex]sinalpha= frac{4}{3}*frac{3}{5}= frac{12}{15}= frac{4}{5}\ sinalpha= frac{4}{3}*(-frac{3}{5})= -frac{12}{15}= -frac{4}{5}\ tg>0 w cwiartce 1 i 3 \ Dla 1 cwiartki\ 3*frac{4}{5}+2*frac{3}{5}= frac{12}{5}+frac{6}{5}=frac{18}{5}=3frac{3}{5}\ Dla cwiartki 3 \ 3*(-frac{4}{5})+2*(-frac{3}{5})= -frac{12}{5}-frac{6}{5}=-3frac{3}{5}\ Licze na aj :)[/latex]
