Answer:
It is decreasing and function represent relationship between coins value is

Explanation:
Given: Value of Coin = $ 550
Rate of Decrease of value of coin = 10% per decade
To find: Function that define relationship between coins value.
let n be the number of decade.
then value of coin after n decade is given by function, f(n)


Clearly we are given rate of decrease of coins value.
So. It is Decreasing.
Therefore, It is decreasing and function represent relationship between coins value is
