The ponytail palm takes its name from its resemblance to hair cascadeing out of a ponytail. It's also called a "bottle palm" because its trunk becomes a bottle like bulb at soil level. Because of its massive size the plants are mostly root-bound. While they can store water in their bulb, and use their water slowly, they probably don't have a lot of soil in their pot. If the roots become too dry the lower leaves turn brown or yellow and the plant looks a little ashy.
These are durable high light plants. They take up a lot of room and the leaf edges are rather sharp.
Remove discolored lower leaves. Do not trim brown off the ends. Brown is normal and more cutting will produce more brown, plus a jagged edge.