moderators if this isn't the appropriate sub forum please redirect the post, thanks)

Hello friends

Say I have two values A and B; I also have a given number of days (or "steps"), nominated Z. to reach from A to B by any mathematical operation. if I wanted to do it linearly the equation would be

(A-B)/Zwould give me the subtraction element I must subtract from A every day to reach B in Z days.

let

A = 1.6

B = 1

Z = 25 (these are my actual numbers I need to calculate btw)

so (1.6-1)/25 = 0.024 is my answer.

BUT what if I need to get to value B exponentially, so that the rate of change is increasing with every day passing? how do I solve that?

thanks!