HP Prime Program using Solve function

[Gene222]

(02-04-2020 12:29 AM)roadrunner Wrote:  Three comments:

1. From a program, solve() has to be sent to CAS via a string;
2. The variable you are solving for should not exist. In the edited program below I used lower case z. You have to use a variable that doesn't exist anywhere on your calculator;
3. Solve doesn't assign the answer to the variable, it just returns an answer; you have to assign that to a variable in your program.

Can you tell us why in a program using fsolve, the variable you are solving for should not exist anywhere on the calculator?