ABSTRACT
An electric signal is a voltage or current varying with time in a manner that conveys information. A signal is defined as a real-valued function of time. By real valued we mean that for any fixed value of time, the value of the signal at that time is a real number. https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780203743102/9cca8f32-4688-4a1e-80c2-a6c9068f5153/content/pg165.tif"/> Note: Voltage is used to designate the waveform equation; current could be used equally as well.
