HP / TI Math Capabilities

Can somebody PLEASE give me some direction as to how you can easily perform basic mathematical operations on the HP33S (preferably) or on the TI33 Series, to include Linear Interpolation (of most importance), Quadratics, etc? As you are well aware, we do not have the luxury of consideration of full "elbow grease" to be leveraged on this bad boy - I am taking the Civil PE on Friday.

Work with me here. Please give me something that doesn't involve some crazy algorithm or ridiculous input that will not end up working.

I tried this for the HP33S and wasted my time. Surely there is a straight-forward path.

Type in these keys ---> [green] PRGM [green] LBL X [green] INPUT A [green] INPUT B [green] INPUT C [green] INPUT D [green] INPUT F [purple] EQN (B-A)*(F-D)/(C-A)+D ENTER [purple] RTN (Press C to exit)

Program Displays ---> PRGRM TOP X0001 LBL X (Note: You can choose letter) X0002 INPUT A X0003 INPUT B X0004 INPUT C X0005 INPUT D X0006 INPUT F X0007 (B-A)*(F-D)/(C-A)+D X0008 ENTER X0009 RTN

Press EQN X, Then it'll ask you to input A,B,C,D,F. Press the "R/S" button after input each variable and not the "ENTER" button. The answer should be shown after you input the "F" value.

Um. WTH?

Scot said:

Can somebody PLEASE give me some direction as to how you can easily perform basic mathematical operations on the HP33S (preferably) or on the TI33 Series, to include Linear Interpolation (of most importance), Quadratics, etc? As you are well aware, we do not have the luxury of consideration of full "elbow grease" to be leveraged on this bad boy - I am taking the Civil PE on Friday.
Work with me here. Please give me something that doesn't involve some crazy algorithm or ridiculous input that will not end up working.

I tried this for the HP33S and wasted my time. Surely there is a straight-forward path.

Type in these keys ---> [green] PRGM [green] LBL X [green] INPUT A [green] INPUT B [green] INPUT C [green] INPUT D [green] INPUT F [purple] EQN (B-A)*(F-D)/(C-A)+D ENTER [purple] RTN (Press C to exit)

Program Displays ---> PRGRM TOP X0001 LBL X (Note: You can choose letter) X0002 INPUT A X0003 INPUT B X0004 INPUT C X0005 INPUT D X0006 INPUT F X0007 (B-A)*(F-D)/(C-A)+D X0008 ENTER X0009 RTN

Press EQN X, Then it'll ask you to input A,B,C,D,F. Press the "R/S" button after input each variable and not the "ENTER" button. The answer should be shown after you input the "F" value.

Um. WTH?

Click to expand...

You'll be better off using the time spent to figure out this program on *studying*. It's unlikely you'll need to solve for roots of a quadratic. You should be able to quickly interpolate table values by just setting up the proportions by hand - heck, you could just "eyeball" it and get close enough for an answer. Or... use nomographs where interpolation isn't required!

You could always use the built-in linear regression and enter in the two "known" points (be sure to put the y-value on the stack first!)... the calculator will give you m and b for the equation y=mx+b.

Still... I'm someone here can offer you a program that will work with the 33.

The TI will barely add. The Casio has this ability, but it's not RPN. I would concur with IlPadrino above...you aren't going to be asked superhard equations. Remember that if you get close you can always try trial and error with all four possible answers probably faster than the stack you described.

Good luck!

Is a TI-33 even allowed? I thought TIs had to be variants of the TI-30.

You're making too much work out of something simple. Instead of using the Program (PRGM) function, use the Equation (EQN) function.

For instance, for linear interpolation I simply put in:

I=B-(H-X)/(H-L)*(B-S)

You are welcome to choose your own variable names.

And for the quadratic simply use the old

X=(B+/-SQRT(B^2-4*A*C))/(2*A)

QED

*Note, I use brackets because I still use algebraic input rather than RPN.

Capt Worley PE said:

Is a TI-33 even allowed? I thought TIs had to be variants of the TI-30.

Click to expand...

TI-33s is permitted by NCEES, which is what I used on the exam. I found that you can get by with a basic scientific calculator. There isn't much hardcore mathematics.