A function of the form: A = P(1-r)ⁿ [OR if (1-r) <1, the function is decaying1)
1) y = 100(1-1/2)ⁿ = decay because 1-1/2 = 1/2 <1
2) y =0.1(1.25)ⁿ = growth because 1.25 >1
3) y = [(0.03)¹/²]²ⁿ = decay because 0.03¹/² = √0.03 = 0.17 <1
4) y = 426(0.98)ⁿ = decay because 0.98 <1
5) y = 2050(1/2)ⁿ = decay because 1/2 <1
