Sinus kąta ostrego jest równy . Wówczas
cosα=14\displaystyle \cos\alpha= \frac{1}{4} cosα=41\displaystyle \cos\alpha= \frac{1}{4}
cosα=74\displaystyle \cos\alpha= \frac{\sqrt{7}}4{} cosα=47\displaystyle \cos\alpha= \frac{\sqrt{7}}4{}
cosα=716\displaystyle \cos\alpha= \frac{7}{16} cosα=167\displaystyle \cos\alpha= \frac{7}{16}
cosα=1316\displaystyle \cos\alpha= \frac{\sqrt{13}}{16} cosα=1613\displaystyle \cos\alpha= \frac{\sqrt{13}}{16}
d2f87358-630d-4f4b-97ae-fb4a18a29744
(nowa formuła)
