Formal Definition for a Stable System
A system is stable if for all bounded input functions x(t)(system approaches +/- infinity) there exists an output y(t) where y(t) is less than a constant M (Bounded inputs yield bounded outputs, system does not approach infinity)
Formal Definition for a Non-Stable System
A system is not stable if there always exists an bounded input x(t) such that the absolute value of the output y(t) is greater than any y(t) calculated thus far.
