Integrals are summers so they can increase without bound over time. But if the input function varies around y=0 -- as many do -- they can remain stable. Now le

Integrals are summers so they can increase without bound over time. But if the input function varies around y=0 -- as many do -- they can remain stable. Now let's talk about infinities that can happen instantly: What's the derivative at the upward edge of a square wave?