The Museum of HP Calculators

HP Forum Archive 18

 How to find "inverses?"Message #1 Posted by PhysicsNerd on 26 Nov 2007, 12:05 a.m. How do you find inverses? (the one where you swap x and y and solve for y) I've looked through the manual and it says to press the button 1/x but isn't that only the reciprocal?

 Re: How to find "inverses?"Message #2 Posted by Vieira, Luiz C. (Brazil) on 26 Nov 2007, 12:19 a.m.,in response to message #1 by PhysicsNerd Hi; just want to help, and would like to know: 1 - which calculator are you using? 2 - can you give us an example of what do you want to compute? The second question of mine is mainly to understand what do you mean by swap x and y and solve for y. Cheers. Luiz (Brazil)

 Re: How to find "inverses?"Message #3 Posted by PhysicsNerd on 26 Nov 2007, 12:24 a.m.,in response to message #2 by Vieira, Luiz C. (Brazil) Oh, my bad; I'm using an hp50g. I would like to graph the inverse of x^2 or abs(x). I would also like to find the inverse of sec (x), with x being any real number within the domain of sec. I just want to find the inverse of a function like: y=x^2 the inverse would be g(x)= +/- sqrt(x) Edited: 26 Nov 2007, 12:26 a.m.

 Re: How to find "inverses?"Message #4 Posted by Tim Wessman on 26 Nov 2007, 12:26 p.m.,in response to message #3 by PhysicsNerd Make a little program like this. If I am understanding correctly, that is how I did it back in high school. It won't work for some functions though. << 'X' ISOL 'Y=A' SUBST 'X=Y' SUBST 'A=X' SUBST >> TW

 Re: How to find "inverses?"Message #5 Posted by PhysicsNerd on 28 Nov 2007, 1:33 a.m.,in response to message #4 by Tim Wessman Are you telling me that the hp50g doesn't have a built-in button for finding inverses? Unfortunately, I don't know how to program. =/

 Re: How to find "inverses?"Message #6 Posted by Walter B on 28 Nov 2007, 1:37 a.m.,in response to message #5 by PhysicsNerd Fortunately, this is an opportunity for you to start learning ;)

 Re: How to find "inverses?"Message #7 Posted by Ed Look on 28 Nov 2007, 10:17 a.m.,in response to message #5 by PhysicsNerd What calculator does?? I agree, you'll have to write the program yourself. And just start with the manual just to get your feet wet; then try to obtain a copy of the HP 48G Advanced User's Reference guide. It should be still available in book form from Calcpro.com for about thirty bucks or so. I believe also it's available on Eric Reichlin's HP48 site in the download section electronically as a .pdf file. This manual is very worthwhile. I was able to use it to get myself to a point at which I can begin to believe I can program almost anything, given reasonable time and maybe a few days more, on a HP-48G series or 49G series machine, which does include the HP-50g. One caveat: I did learn to program back in high school and college, even if that was back just shortly after stone tablets got obsolete, HP programmable scientific calculators and a "real" computer language. But if as you say you don't know how to program, then I would strongly recommend you start with the 50g manual, then get that AUR I mentioned in this message. Edited: 28 Nov 2007, 10:20 a.m.