3.1 X(eo)=2xnJe-jon where x[n] is a real sequence. Therefore X(e)=Rl∑xnlo/。 ∑xR(-mu)=∑ x[n]cos(on),and xmm)=m∑刈nm∑刈mc-m)=-2 xn] sin(oon) Since cos(on)and sin(on)are, respectively, even and odd functions of o, Xre(eJo) is an even function of o
Part i Vocabulary Structure(25%) Directions: There are 25 incomplete sentences here, each with a blank. You are required to complete each one by choosing the most appropriate answer from the 4 choices marked A.B.c and D 1. Molly watching football matche T B. interested C. ke