HP HP-28S - Page 60

Clear the stack and select the cursor menu .
• 1 CLEAR I
If a menu is displayed, press GEJ to select the cursor menu.
Put the name I F.: 1 I on the stack.
~ R1 1 ENTER I
Iii
'R! ,I
Note that the closing I is added for you. You'll leave Rl on the stack
until it's time to add it to the rest of the calculation.
Put the reciprocal of R2 on the stack.
~ R2 1 ENTER I .[}E] '"'4:-:-------------,
3:
2:
1 :
'Ri'
, INV(R2) ,
Put the reciprocal of R3 on the stack.
~ R3 1 ENTER I .[}E] 0.
4
-:":------------,
3: 'Ri'
Add the reciprocals of R2 and R3.
CD
Take the reciprocal of the sum .
• [}E]
2: 'INV(R2)'
1: ' INV(R3) ,
4:
3:
2:
1 :
3:
, Ri'
'INV(R2)+INV(R3),
2: 'Ri'
1: 'INV(lNV(R2)+INV(R3)
) ,
4: Repeating Calculations 59
I