Need an example for exponential decay ia? Help me please

[periperishh]

Hi, i really need an example of maths ia on the topic of exponential decay/growth. i ve been stucked for a quite long time because i couldnt get any example of exponential. since most of the example focused on statistic. i really need one to make sure that im on a right track. 

[Martijn.S]

Try having a look at radiative decay and half life. That is the most common exponential decay/growth that I know of. For growth, I'd say cell division (especially cancerous cells).

There are a couple of good examples on Wikipedia, for both decay and growth:
Growth: https://en.wikipedia.org/wiki/Exponential_growth#Examples
Decay: https://en.wikipedia.org/wiki/Exponential_decay#Applications_and_examples

Good luck.

[tim9800]

As Martijn said above, radioactive decay is a great choice if you have some background in Physics - it will allow you to incorporate PE in your IA simply by saying "I was interested in the concept of radioactive decay in my physics class, but I wanted to develop it further mathematically". Another example I can think of, but for Chemistry is reaction rates. As the products of a reaction increase, but at a decreasing rate, the reactants decrease, also at a decreasing rate. Though I don't do HL, I have glimpsed over a few articles doing my Chemistry IA about orders of reaction, though I believe they are more to do with rational functions (hyperbolas) than exponential graphs. The pH scale is also a good go-to, as it uses a log base 10 scale.