If X1(k) and X2(k) are the N-point DFTs of x1(n) and x2(n) respectively, then what is the N-point DFT of x(n)=ax1(n)+bx2(n)?
A. X1(ak)+X2(bk)
B. aX1(k)+bX2(k)
C. eakX1(k)+ebkX2(k)
D. None of the mentioned
Answer:A
If X1(k) and X2(k) are the N-point DFTs of x1(n) and x2(n) respectively, then what is the N-point DFT of x(n)=ax1(n)+bx2(n)?
A. X1(ak)+X2(bk) B. aX1(k)+bX2(k) C. eakX1(k)+ebkX2(k) D. None of the mentioned
Explanation: We know that, the DFT of a signal x(n) is given by the expression