All the items use the same form of exponential equation:
In this form, the initial value is always "a", because for t = 0:
And whether it is a exponential growth of decay we can see by the "b" value.
It is an exponential growth if:
And it is an exponential decay if:
So the initial value is 2 and "b" is less than 1, so it is an exponential decay.
b)
So the initial value is 2 and "b" is greater than 1, so it is an exponential growth.
c)
So the initial value is 2/3 and "b" is greater than 1, so it is an exponential growth.
d)
So the initial value is 2/3 and "b" is less than 1, so it is an exponential decay.
e)
So the initial value is 3/2 and "b" is less than 1, so it is an exponential decay.