$cos224=-cos44$ öte yandan $tan68=cot22=\frac{cos22}{sin22}=\frac{\sqrt{\frac{1+cos44}{2}}}{\sqrt{\frac{1-cos44}{2}}}=\sqrt{\frac{1+co44}{1-cos44}}$ Dolayısıyla $m^2=\frac{1+cos44}{1-cos44}\Rightarrow cos44=\frac{m-1}{m+1}\Rightarrow -cos44=\frac{1-m}{m+1}$ olacaktır.