화 간 cos(X-30°)+sin(X+30°)+cosX+1

화 간 cos(X-30°)+sin(X+30°)+cosX+1

cos(X-30°)+sin(X+30°)+cosX+1=cosX*cos 30°+sinX*sin 30°+sinX*cos 30°+cosX*sin 30°+cosX+1=[(근호 3+1)/2]sinX+=[(근호 3+2)/2]cosX+1