Question 1158089
{{{cos(pi/12)=cos(4pi/12-3pi/12)=cos(pi/3-pi/4)=cos(pi/3)cos(pi/4)+sin(pi/3)sin(pi/4)=(1/2)*(sqrt(2)/2)+(sqrt(3)/2)*(sqrt(2)/2)=highlight((sqrt(6)+sqrt(2))/4)}}}