00:01
So what's a way to write an exponential function? well, it's always written as a times b to the x, where a represents my start value, b represents my growth or decay rate.
00:12
It's a growth rate if i'm multiplying by a value greater than one, decay if it's less than one.
00:17
So let's say the population is growing 3 .1 % per year.
00:20
It was 1250 in 2010.
00:23
So let's say x is years after 2010.
00:28
So my start rate will be my 2010 population, which is 12 ,500, okay? and i'm growing at a rate of 3 .1%.
00:43
Okay, so i need my original population plus 3 .1 % each year.
00:48
But whenever i have a percent, i'm gonna write it as a decimal.
00:51
How do i do that? divide by 100.
00:53
So this would be 12 ,500 times one plus 0 .031.
00:58
And this is each year.
00:59
So raised to the x power...