Question

What is the equation of the graph?

Answer 1

The general shape is that of an exponential function. Since the horizontal asymptote is -3, it appears to be shifted down 3. The y-intercept is 1 unit above the horizontal asymptote, so it appears there has been no horizontal shift.

For x=1, the curve goes through a point 6 units above the horizontal asymptote. This suggests the equation is
  y = 6^x - 3