Which graph represents an exponential function?

The answer to your question is the third one

Step-by-step explanation:

The first graph is the graph of a

The second graph is of a rational function

The third one is of an exponential function

The Third graph shows the exponential function

The exponential function can be given by the equation (1) as

Where is any number

The domain  ( X values) of an exponential function is all  Real numbers

The range (Y values ) of an exponential function is all positive real numbers

For a special case

b = e =2.718281828459045

The Third option is a graph of

As the graph  is having -x in exponent as compared to +x so the graph will be inverted with respect to y axis.  

For more information please refer to the link below

link

yes because there is exactly one y value for every x value

for function there can't be more than one value for every x value