solve() problems

[HansB]

(06-05-2021 07:06 AM)Joe Horn Wrote:  

(06-04-2021 07:51 PM)HansB Wrote:  ... Now on my Home screen using solve() function does not give me any solutions, just X. For instance taking the simple example from the solve() Help:
solve(X-3=1) -> X

Two problems here. (1) Home view is intended for floating-point number crunching, not symbolic math manipulations or exact calculations. That's what CAS view is for. (2) Notice that all the examples for solve() in the Help system use lowercase 'x', which causes a syntax error in Home view when no value has been stored in the variable 'x' yet. This serves as a reminder to you that solve() is a function that performs symbolic math manipulation, so you should only use it in CAS, where undeclared variables are treated symbolically as expected, instead of as syntax errors.

You can force Home to treat uppercase 'X' as a symbolic variable (which it isn't really) by putting your algebraic expressions in single quote marks like this:
solve( 'X^2-3=1' , 'X' )
but that's silly. Use CAS for CAS problems, and use Home for number crunching.

Ah, thank you! That is very helpful and solves my confusions! A real beginner's error!