HP Prime Graphing Calculator - Manual (Page 428)

422 Functions and commands
3. In the Function field, enter the function.
eA A >+fA B >A C
New fields appear
below your function, one
for each variable used in
defining it. You need to
decide which ones are
to be input arguments
for your functions and
which ones are global
variables whose values
are not input within the function. In this example, we’ll
make A and B input variables, so our new function takes
two arguments. The value of C will be provided by global
variable C (which by default is zero).
4. Make sure that A and B are selected and C is not.
5. Tap .
You can run your function by entering it on the entry line
in Home view, or be selecting it from the USER menu. You
enter the value for each variable you chose to be a
parameter. In this example. we chose A and B to be
parameters. Thus you might enter SINCOS(0.5, 0.75).
With C=0 and in radians mode, this would return
1.211…