HP 40gs HP 39gs_40gs_Mastering The Graphing Calculator_English_E_F2224-90010.p - Page 356

One additional step is required. For some reason the Parametric aplet doesn't seem to properly accept the functions. If you press PLOT now you will receive the "Undefined Name" error. The trick is to highlight each function in turn and press . Don't make any changes, just press ENTER or . This seems to make the calculator accept that it is a valid function, since it has had the chance to examine the function as if you had typed it in yourself. Pressing PLOT at this point will produce the screen shown right. The symmetry we predicted earlier is now visible. This may not be the best possible view and you may wish to use PLOT SETUP to change this. ix. The final step is to accurately evaluate f ⎛ ⎜⎝ π 3 ⎞ ⎟⎠ . To do this, return to the CAS and enter the following: ALPHA X 1 ( SHIFT 3 3 SHIFT ALPHA Y 1 ( SHIFT 3 3 SHIFT (Notice the brackets appear when you press .) We can now evaluate the left hand coordinate, then the other. The first enter substitutes the value, the second gives the answer. ENTER ENTER ENTER ENTER 356