[latex] \frac{2cos(\frac{3 \pi }{2} ) - sin(- \frac{3}{2} + \beta )}{ 5cos( \beta - \pi )}[/latex]

[latex] \frac{2cos \frac{3 \pi }{2}-sin(- \frac{ 3\pi }{2}+ \beta ) }{5cos( \beta - \pi )} = \frac{2*0-sin(-( \frac{ 3\pi }{2}- \beta ))}{5*cos(-( \pi - \beta ))} = \frac{-(-sin( \frac{ \pi }{2}- \beta ))}{5*cos( \pi - \beta )} = \frac{cos \beta }{-5cos \beta } [/latex] [latex]=- \frac{1}{5}=-0,2 [/latex]