cos\alpha=0,5^{0,5}
źródło:
cos\alpha=0,5^{\frac{1}{2}}
cos\alpha=\sqrt{\frac{1}{2}}
cos\alpha=\frac{1}{\sqrt2}*\frac{\sqrt2}{\sqrt2}
cos\alpha=\frac{\sqrt2}{2}
\alpha=45^0 odp.