Keyboard Mapping:

The function keys that appear on the calculator are mapped to the Function keys F5 - F15 on the Apple Extended Keyboard.  Here is the correspondence map:
F5=sin
F6=cosine
F7=tangent
F8=2nd Function
F9=Value of PI
F10=Natural Log
F11=Base 10 Log
F12=Backspace Key
F13=Power function
F14=Square root function
F15=Square function

Shift + F5=arc sin
Shift + F6=arc cosine
Shift + F7=arc tangent
Shift + F9=Factorial function
Shift + F10=Constant e raised to a power.
Shift + F11=Constant 10 reaised to a power.
Shift + F13=Nth Root function
Shift + F14=Cubed Root function
Shift + F15=expression 1 divided by x

Other keys mapped to functions on the calculator:
c, Clear=Clear function***
ESC = (Same as Clear/No Function)***
*, x=Multiplication
X=Memory Enter
R=Memory Recall
M=Memory Add
?=About Dialog box
Delete=Backspace function
Enter=Equal function
` or . = Reverse sign of number on display***
% = Percent increase or decrease.

Shift + Clear or Esc = Clear Last Entry, not just last digit.
Clear + X = Clear Memory.
2nd Decimal point in any number = reverse sign of number ***

***Depends upon settings in Preferences Dialog Box.