Apple Newton Works Graphing Calculator - Manual (Page 19)

x and t in the above examples are the function parameters. You specify the values
for these parameters when you use the function in a calculation. For example,
to evaluate the function
z(x)=sqrt(16–x^2)
with x = 2, type
z(2)
and
press Enter.
To create a function:
m Enter the function and press Enter.
If no errors are found, a checkmark appears to the right of your function and your
function is added to the Your Functions list. Functions are saved automatically. There
is no save command or button.
Using Functions and Variables 19