2.1 Step, Impulse, Ramp, Sinusoidal, Exponential,and University of California, Davis DC Signals Zhen Wan Step Function. The Impulse. Ramp Function.Sinusoidal FunctionDCSignal University of California, Davis 2.2 Ideal and Practical Sources Clayton R. Paul Ideal Sources. Practical Sources University of Kentucky, Lexington 2.3 Controlled Sources What Are Controlled Sources? What Is the Significance of J. R. Cogdell