0" alt="\frac{sin3x+sin5x}{2sin2x}=\frac{2sin4x\cdot cosx}{4sinx\cdot cosx}=\frac{2sin2x\cdot cos2x}{2sinx}=\frac{2sinx\cdot cosx\cdot cos2x}{sinx}=\\\\=2cosx\cdot cos2x=2cos240^0\cdot cos480^0=2cos(180+60)cos(360+120)=\\\\=2(-cos60)cos120=-2cos60cos(180-60)=-2\cdot \frac{1}{2}(-cos60)=\\\\=+cos60=\frac{1}{2}>0" align="absmiddle" class="latex-formula">