Pardon me for the dumb looking question but I'm trying to comprehend a "signals and systems" subject and relate it to voltage or current signal.
A periodic signal is made up of sinusoids which is a conclusion of Fourier series. This series has the complex exponential form which means to me that a signal can be represented as sum of exponential functions.
And for a complex exponential which can also be written as cos(ὦt)+jsin(ὦt), the "Cosine" part is called the real part of a complex exponential.
So when we see any voltage waveform on a scope screen or when we view a sampled voltage data, does that actually mean the voltage signal we are dealing is made up of only cosines but no sines?
I might be confusing real part aka cosine part of the signal representation and a voltage signal which is also called a real signal. But totally confused what is meant by these..