Question

Se considera E(x) =sin 2x supra 3-cos8xsupra3 aratati ca nr E(Pi supra 4) este natural

Answer 1

E(pi/4)=sin[(2*pi/4)/3]-cos[(8pi/4)/3]=[sin pi/6-cos2pi/3]=1/2+1/2=1
am tinut cont ca
cos2pi/3=2cos^2(pi/3)-1=2*1/4-1=-1/2