An expo fn, such as y = e^x, has neither max nor min. The graph of y = e^x begins in Quadrant II and ends in Quadrant I; it has no upper limit. As x becomes smaller and smaller, the graph approaches, but does not touch, the x-axis.
An exponential function has a range that extends to infinity from near its horizontal asymptote of 0. There is a lower limit, but no minimum. There is no upper limit, hence no maximum.
