How To Calculate Growth Rate

Hi, I'm Peter Edwards from Bluetutors. We teach children of all ages, right from primary school to degree level, and we find the highest quality tutors. Today, I'm going to teach you some maths.

Okay, so now we're going to calculate growth rate. So fairly obviously, growth rate is the rate at which things grow. So we have an example on the board here, from which we have taken the population of rabbits, which is quite a common one to use, and we're assuming that every year, these rabbits essentially double.

So in year one, we have two rabbits, year two, we have four rabbits, year three, we have eight rabbits and year four, sixteen rabbits. I've plotted those on this graph here. This graph has the equation R equals T to the power of two.

So, that's fairly obviously the growth rate of this, you can see it doubling every year. If you want to work out the growth rate of an equation, let's say we have the equation X equals three T squared plus two T plus 1, where X is at a thing which is growing, the growth rate of this would be the differential of X, with respect to T. So in this case, that is six T plus two.

So at any given time, with a particular T, you can work out the growth rate of X from differentiating that equation. That's how to calculate growth rate. .