Hi Yasin,
As the error log suggests, " Unrecognized function or variable 'b' " describes that the variable 'b' is not yet created while the execution is in that line.
And, as you are calling a function to get the 'b' values, the 'b' values may not have returned after the function execution. Please ensure that the 'b' values are returned from the function and are stored in a global variable 'b', so that c=b*(x^2)+4 works. If 'b' is declared within a function, its scope will be within that function only. It cannot be accessed outside the function, it has to be returned to global/main. You can have breakpoints to verify whether 'b' is created while the execution is in line c=b*(x^2)+4.
Hope this answers your query!
