Answer:
h=3.9x+15.85 meters
Step-by-step explanation:
Let's say that the height of the floor just before the roof to the highest point of the roof is also 3.9 m, perhaps, we have an almost flat roof
Since the FM radio antenna is fixed on top of roof, the total height is that of previous floors and the antenna
Taking the building to have x number of floors with each floor having 3.9 m height, the function of height will be
h=3.9x + 15.85 meters