Dquations provided using functional notation should be entered without the functional notation because syntactically "f(x)" is equivalent to "the variable f multiplied by the variable x, in parentheses". So to simply graph a function within a new worksheet or to use the function in a non-Function wizard, replace "f(x)" with a single variable, such as "y".

Using Algebrator, there is a Function Wizard titled 'Evaluate a function', which enables you to easily work with functional notation.  In contrast, using doyourmath.com you are correct to replace the intended variable 'x' of '-2' with '(-2)'. 

To help you clearly understand our desktop software and how appropriate it may be for your needs, please use one of the following links to obtain a free trial of the program:

Windows: https://www.softmath.com/tr/alg51win-tr-en.exe

Mac: https://www.softmath.com/tr/alg51mac-tr-en.dmg