Question 1028370
{{{cosx*siny =(1/2)(sin(x+y) - sin(x-y))}}}

==> {{{cos((5pi)/12)*sin(pi/2) =(1/2)(sin((6pi)/12) - sin((4pi)/12))}}}

===> {{{cos((5pi)/12)*sin(pi/2) =(1/2)(sin(pi/2) - sin(pi/3)) = (1-sqrt(3)/2)/2 = (2-sqrt(3))/4}}}