64. A 4*4 DFT matrix is given by
1\2 1 1 1 1
1 x -1 y
1 -1 1 -1
1 -j -1 j
(j^{2}= -1)
Where values of x and y are ---------,------------- respectively.
(1)1,-1
(2)-1,1
(3)-j,j
(4)j,-j
Ans. is 4
4 X4 DFT matrix Def
1/N 1 1 1 1
1 w w^2 w^3
1 w^2 w^4 w^6
1 w^3 w^6 w^9
In this ex.
given that (j^{2}= -1)
=> here w=x
x^2=-1 and j^2=-1
i.e. x=j
w^3=y
w^3=-j
i.e. y=-j