Solving with the built-in equations of the 35s

[Palmer O. Hanson, Jr.]

Page 7-6 of the 35s manual describes use of the built-in equations from the keyboard. I would like to use the "2x2 lin solve" equation in a program. How do I do that?

[Gene Wright]

This should show how. Good to finally meet you a few weeks ago in Nashville!

Learning Module

[Andrew Feist]

I don't think you do--I think you can only type your own equations into a program, not use the ones that are built in.

[Gene Wright]

Ah, I mis-read your original question.

You cannot use one of the built-in equations in a user program. Sorry!

[Dieter]

You cannot use equations from the 35s equation list in your own programs. But solving a 2x2 system is so trivial that it can be done in a very short user routine:

RCL A

RCL* F

RCL D

RCL* C

 -

RCL A

RCL* E

RCL B

RCL* D

 -

 /

ENTER

RCL* B

+/-

RCL+ C

RCL/ A

This returns the two unknowns in X and Y.

Actually you can also do this in just two lines, using the EQN-feature:

([A,D]*[F,-C])/([A,B]*[E,-D]>G)

([C,B]*[E,-F])/G

Type "STO G" to enter ">G". Please also note that the minuses are unary (signs, not operators). This solution also works for A=0. ;-)

Dieter

Edited: 17 Oct 2012, 3:28 p.m.