This is an online grapher for exponential decay functions of the form \[ a(t) = A e^{- r t} \] where A is the initial amount (or population), r is the rate of decrease and t is the time.
Exponential decay functions are very important as they are used to model situations in physics, chemistry, eletricity, economics...; hence a thorough understanding of this class of functions is necessary for their proper use in the listed fields of applications.
To gain better understanding of exponential decay functions, we need to compare two or more of these functions with different parameters A and r. One way to understand the effect of each of the two parameters is to fix one of the parameters, r for example with r1 = r2, and assign different values to A1 and A2 which will make it easy to understand the effect of A.