Question 981955
{{{sin(x)+sin(y) = 2*sin((x+y)/2)*cos((x-y)/2)}}}



{{{sin(90)+sin(30) = 2*sin((90+30)/2)*cos((90-30)/2)}}}



{{{sin(90)+sin(30) = 2*sin(120/2)*cos(60/2)}}}



{{{sin(90)+sin(30) = 2*sin(60)*cos(30)}}}



{{{sin(90)+sin(30) = 2*((sqrt(3))/2)((sqrt(3))/2)}}}



{{{sin(90)+sin(30) = 3/2}}}