Answer:
Decay
Explanation:
We are given an equation

We need to say about decay or growth of exponential function.
Exponential function:

Where,
- a is initial value of exponential function.
- b is decay or growth of function
For decay: 0<b<1
For growth: b>1
Now we rewrite the equation into this form

Changes to

Here, b=0.5 < 1
Therefore, The given function would be decay.
Thus,
is deacy.