If the noise is too large it's impossible recognaize the signal.

If the noise produce some errors it's impossible recover the original signal.

We can extract the signal from a noisy environment if the noise is not too large.

The same of the analogic value

similar to main value of the analogic signal

The value of analogic signal in a instant of time.

Bandpass filter

Lowpass filter.

Highpass filter

Noise, frequency and energy.

Wave, power and energy.

Phase, frequency and amplitude.

Because electromagnetic wave behave like this function

Because is the most used math function in engineering

Because we can descompose all functions in the sum of sinusoidal functions

Periodic sawtooth signal

non-periodic signal

Wave with highest frequency

If its necessary appears noise

If its necessary appears like a periodic signal between zero and frequency sampling.

Doesn't appear energy out of the band

Change and increase the amplitude of a group of frequencies

Reduce the amplitude under a prefixed level the frequencies that we choose.

Delete all the frequencies that we want.

we can add two or more signals if there is no noise.

Send electromagnetic signals in the absence of noise.

if y1 and y2 are the response to the input sequences x1 and x2, respectively, then the input ax1+bx2 produces the response ay1+ay2.

The value that allows our hardware.

The value double of the maximun frequency.

The value higher of the maximun frequency.