symbolic constants in CAS

[Han]

On the HP Prime, there is a major difference between 'A' and 'a' besides one being uppercase and the other being lowercase. The variable 'A' is always a real-valued variable and can never be undefined. On the other hand, 'a' may be treated as an undefined variable. What you likely experienced was that using 'A' in your calculations will actually convert 'A' to the value stored in this variable.

Try using the laplace command but with undefined variables such as 'a'. If for some reason 'a' seems to not work, then it may be the case that you had previously stored a value into 'a'. To make matters worse, the 'a' as a variable created in Home view is different from the 'a' variable created in CAS view. To ensure that all versions of the variable 'a' are "deleted" you can use the memory browser to delete the Home view version, and purge(a) to delete the CAS version.