HP49G / HP49G+ Tutorials
Part 2 - Data Entry
Now everything is setup, how do we use this thing?
RPN Usage Examples
RPN is a handy method for entering formula. It is not the only way - there is also Standard Algebraic (used in TI calculators) and the Equation Writer (handy for entering equations exactly as you see them on paper)
RPN is where you enter the numbers, then press the operators. Why on earth would you want to do this?
Note: Calculations are done in Symbolic Exact mode for clarity. If Numeric mode is set, there is no need to press ->Num but calculations are harder to follow.
Example One:
Find 1 / ( 1/5 + 1/6 + 1/7) (Equivalent Resistance of 5 , 6, 7 Ohm resistors in Parallel)
Empty Stack - Just turned it on
Press 5
Press 1/x key
Press 6
Press 1/x key
Press 7
Press 1/x key
Press +
Press +
Press 1/x key
Press ->Num To give an inexact numerical result
Example 2: Find e^ (root 2) / ( e^ (root 2) + 1 )
Press 2
Press square root key
Press e^x key
Press ENTER to make a copy of the Top of Stack - Copy e^ (Root 2 )
Press 1
Press +
Press Divide
Press ->Num To give an inexact numerical result
Example 3: Find the derivative of Cos(Sin(x)) with respect to X
Press X
Press Sin
Press Cos
Press 'Shift 4' To bring up the calculous menu
Press 'DERVX' Softkey (find Derivative with Respect to X)
If you make a mistake, simply hit the 'undo' key.
Algebraic Entry
OK, so that's great, but what if you want to enter an expression algebraically? Easily done. If you are in RPN mode, press the '' (tick) key, and type your formula as you would on a normal calculator.
The Equation Writer
But the Equation Writer is the best way to copy expressions from paper. Suppose you wish to integrate sin(x) with respect to X between 0 and Pi.
Press 'EQW' To start the Equation Writer
Press the Definite Integral Key
Use the cursor to fill in the bounds
Move the cursor and fill in the expression
Enter 'Respect to X'
Press ENTER to put it on the stack
Press 'EVAL' for the answer.
See The Other Tutorials Here