Question

HELPPPPPP mee

  (cos (11 П)/3)*ctg((-21П)/4)

Answer 1

$frac{11pi}{3}=660\ frac{-21pi}{4}=945$

cos660*ctg945=cos(4*180-60)*(-ctg(5*180+45))=-cos60*(-ctg45)=0.5*1=0.5