oblicz pozostałe wartości funkcji trygonometrycznych wiedząc że alfa (90,180)oraz: cos alfa =-jedna czwarta

[latex]cosalpha=-frac{1}{4}[/latex] [latex]alpha in (90^0,180^0)[/latex] -> druga ćwiartka (tylko sinus jest dodatni) [latex]sin^2 alpa+cos^2 alpha=1[/latex] [latex]sin^2 alpha+(-frac{1}{4})^2=1[/latex] [latex]sin^2 alpha+frac{1}{16}=1[/latex] [latex]sin^2 alpha=frac{15}{16}[/latex] [latex]sin alpha=frac{sqrt{15}}{4}[/latex] [latex]tg alpha=frac{sin alpha}{cos alpha}[/latex] [latex]tg alpha=frac{frac{sqrt{15}}{4}}{-frac{1}{4}}[/latex] [latex]tg alpha=-sqrt{15}[/latex] [latex]ctg alpha=frac{cos alpha}{sin alpha}[/latex] [latex]ctg alpha=frac{-frac{1}{4}}{frac{sqrt{15}}{4}}[/latex] [latex]ctg alpha=-frac{1}{sqrt{15}}[/latex] [latex]ctg alpha=-frac{sqrt{15}}{15}[/latex]