0\\\\Sin\frac{\alpha }{2}=\sqrt{\frac{1-Cos\alpha }{2} }=\sqrt{\frac{1-\frac{1}{2} }{2} }=\sqrt{\frac{1}{4} } = \frac{1}{2}=0,5" alt="\frac{3\pi }{2}<\alpha<2\pi\\\\\frac{3\pi }{4}<\frac{\alpha }{2}<\pi\\\\Sin(\pi-\frac{\alpha }{2})=Sin\frac{\alpha }{2}>0\\\\Sin\frac{\alpha }{2}=\sqrt{\frac{1-Cos\alpha }{2} }=\sqrt{\frac{1-\frac{1}{2} }{2} }=\sqrt{\frac{1}{4} } = \frac{1}{2}=0,5" align="absmiddle" class="latex-formula">