Answer:
The equation that is represented by the graph below is:

Step-by-step explanation:
The graph is a curve such that it has the following representations:
when x=0 it passes through 1.
and also when x → ∞ it goes to ∞
and when x → -∞ it goes to 0.
Hence the function that satisfies all these properties is:

1)
The first function:

is not defined at x=0
2)
the function
at x=0 gives the value:

which does not satisfies the value as in graph.
3)
The function 
satisfies all of the above properties.
4)
The function:

at x=0 gives:

which does not satisfies the point on the graph.
Hence, option 3) is correct.
is the desired function.