No symbolic results using HP prime

[Han]

(05-04-2019 12:42 PM)DuxDucisH Wrote:  Hello, i recently got an HP prime which i found lovely to use. However, i've had some issues that i have no idea of solving. Searching haven't helped and im getting more and more frustrated.

I'll start of with my biggest issue right now. When differentiating equations, i seem to be unable to get an symbolic answer, instead the calculator seems to use the assigned value for the variable in question, and if it doesn't have a value it just uses "0" and gives a numerical answer to that.

Does anybody have an idea what im doing wrong? I'll Attach a screenshot so you can see what i mean. Doesn't seem to make any difference if i use the diff command or the derivate template. Ive tried using both small and large Xs but it doesnt make any difference.

(The following assumes CAS mode, as seen in your screenshot.)

The variable X (upper case) is a system variable and always has a value stored in it, similar to the TI-83 or TI-84 series of calculators. Normally, one would delete a variable (to make it symbolic) and all would be as expected. However, system variables are built-in and cannot be deleted. So use the lower case x for your expressions. If you still get numerical values then it is likely that the lower case variable x has a value stored in it. You can delete the variable (to make it symbolic) via: purge(x).