The way we decide where to put mobile base stations, wireless access points and also radio devices in our smart phones all based on how much power we can give the device and the distance it can cover. Meaning is it going to cover the whole of east London or only Mile End (where my university at ;)).
In order to decide, we use mathematical equations to tell us the maximum distance the coverage area and also how much battery life would be left if we use the device for say 2 days!!
So this means that we can also use maths to tell us that by reducing for example power to 30% I can save battery life by for example again 2 days … Everything we do in engineering and most sciences maths has to put its nose in it so we really need it 🙂
I hope this was not much more confusing that my first statement!!