Given:
The exponential function is:
To find:
The percentage rate of increase or decrease.
Solution:
The general exponential function is:
...(i)
Where, a is the initial value, |r| is the growth rate in decimals if r>0 and |r| is the decay rate in decimal if r<0.
The exponential function is:
It can be written as:
...(ii)
On comparing (i) and (ii), we get
Since r is negative, therefore the given function is a decreasing or decay function.
Now,
So, the rate of decrease is 0.06. Multiply this number by 100 to get the percentage.
Therefore, the rate of decrease is 6%.