ENEL 327 Final Exam

Question 1

What do even functions look like?

Answer 1

Mirrored across y axis

Question 2

What do odd functions look like?

Answer 2

Mirrored across origin (y=x axis)

Question 3

Formula for even functions?

Answer 3

(1/2) (x(n) + x(-n)

Question 4

Formula for odd functions?

Answer 4

(1/2) (x(n) - x(-n)

Question 5

How can you tell if a system has memory?

Answer 5

If the time or n values have been messed with

Question 6

What is invertability?

Answer 6

Different inputs will always give unique outputs

Question 7

What is causality?

Answer 7

The output of a system does not depend on future values

Question 8

What is stability?

Answer 8

If a system is given a bounded input, the output must be bounded

Question 9

What is time invariance?

Answer 9

A time shift in the input must result in the same time shift in the output

Question 10

What is linearity?

Answer 10

[x1 + x2 -> y1 + y2] AND ax1 -> ay1

Question 11

What is the formula for the fourier transform?

Answer 11

integral from -inf to inf of [x(t)e^(-jwt) dt]

Question 12

What is the formula for the inverse fourier transform?

Answer 12

(1/2pi) integral -inf to inf [X(w)e^(jwt) dw]

Question 13

What is the convolution property for fourier transforms?

Answer 13

x(t) * y(t) X(w)Y(w)

Question 14

What is the modulation property for fourier transforms?

Answer 14

x(t)y(t) 1/2pi X(w) * Y(w)

Question 15

FT of cos(wot)?

Answer 15

pi[delta (w-wo) + delta (w+wo)}