looking at the picture above, let's notice that it has a couple of asymptotes, the graph keeps on going next to but never touching the asymptote, let's focus only on the horizontal asymptote.
The horizontal asymptote is a y = 0 or namely the x-axis, the curve from the top, comes down down and down to 0 but never touching it. The curve from the bottom goes up and up and up gets to 0 but never touches it.
So we can assume the graph keeps on going upwards as well as downwards, all the while never touching 0. So its Range is anything BUT zero.