Circuit Theorem

Homework.

They are things every Engineer needs to know about.

An exponential function is one where the rate of change in the size of the function is proportional to the size of the function. The bigger it is: the faster it grows. The world population of people is a good example.

The simplest exponential equation is y=e^x

And the differential i.e. the slope of the curve: dy/dx = e^x

An exponential function always outstrips nearly all other functions in the end.

A sinusoidal function is one which oscillates y= sin(x)

There is no such thing as a step down function. You can get devices which step down physical "things" like a DC to DC converter which steps down say 12V DC to 3.3V DC; or an AC to AC converter (i.e. a transformer) which which converts say 220 V AC mains to 110 V AC (for an electric razor maybe).