Question 924578
{{{-11pi/12=-(10pi/12+1pi/12)=-(5pi/6+1pi/12)}}}

{{{-5pi/6=-150}}}°
 {{{-pi/6= -30}}}° =>{{{-1pi/12 =-30/2=-15}}}°

so, {{{-(5pi/6+1pi/12)=-150-15=-165}}}°

and {{{sin(165)=-0.258819}}}