Section 6: Functions82
Squaring
To square a number in the X-register, execute the X2 and when you execute the function from the display the name is X 2 (using the up arrow, the shifted function on the ENTER  key, in ALPHA mode).
 Keyboard execution: X2 Display execution: X 2
For example, find the square of 27 using the keyboard X2 function:
Keystrokes Display
27 g X2
 729

Now, find the square of that number using the display execution form:
Keystrokes Display

 729

XEQ
 XEQ _ _

ALPHA
X g   g 2    The up-arrow is on the shifted N key in ALPHA mode (on ENTER  key).
ALPHA
 531,441.0000

Using Pi
The value of pi accurate to 10 places (3.141592654) is provided as a fixed constant in your HP-41C. Merely press g   on the keyboard or execute PI form the display whenever you need it in a calculation.
 Keyboard execution: Display execution: PI
For example, calculate the surface of Ganymede, one of Jupiter’s 12 moons, using the formula A = πd2. Ganymede has a diameter (d) of 3200 miles.
Keystrokes Display
3200
 3200 _

g X2
 10,240,000.00

g
 3.1416
The quantity pi.
×
 32,169,908.78
Area of Ganymede in square miles.