Whenever i study differential equations, alot of the questions provide an equation of a specific model of a system at some point in time( particle model, economic model, bacteria growth, radioactive decay, rate of water flow, wind speed, inductance, and impedance etc...). Whenever i solve this in to the desirable form in which the question asks, i notice alot of the forms come in with the mathematical constant "e"
So here is my question, why do alot of things in nature seem to agree with the mathematical constant "e"?