I have a question about how to force the 48G to produce a symbolic derivative. Say I type in an expression like x/y, then y, and hit the derivative button. If there are no variables for x and y, the result is a symbolic solution, i.e -x/y^2, which is what I want. However if there are variables for either x or y the numeric values will be inserted into the resulting expression. I am looking for a way to keep the symbolic result without using the derivative menu.

By contrast on the 50G the result seems to be always be symbolic.

Thanks in advance for any help.