(a)

Observe the scatter plots in a graph,

The plotted dots are appeared as increasing exponentially.

So the function of the graph represents an exponential function.

(b)

Observe the scatter plots in a graph,

The plotted dots are appeared as decreasing way.

when is minimum the value of is maximum.

So the function of the graph represents an reciprocal function.

(a) Exponential function.

(b) Reciprocal function.