-
×InformationNeed Windows 11 help?Check documents on compatibility, FAQs, upgrade information and available fixes.
Windows 11 Support Center. -
-
×InformationNeed Windows 11 help?Check documents on compatibility, FAQs, upgrade information and available fixes.
Windows 11 Support Center. -
- HP Community
- Archived Topics
- Tablets and Mobile Devices Archive
- Solve This Linear System HP50g

Create an account on the HP Community to personalize your profile and ask a question

04-19-2014 04:59 PM
Hi guys,
I am an Electrical Engineer and have to solve systems of linear equations on a regular basis, so that functionality is very important for me. Everything works fine 95% of the time, but sometimes I run into systems that the HP50g does not seem to like. For instance the one below.
I want to solve for x,y,z, and a in terms of V
V-100000x+100000y-100000x=0
-250000y-V+100000x+100000z=0
-250000z+100000a+100000y=0
-250000a+100000z=0
After these 4 equations are on the stack, I make them into a vector by pushing {4} onto the stack and then pressing ->ARRY. Then I push the variables I want to solve for onto the stack, x,y,z, and a and make a vector out of them. Then I use LINSOLV to solve the system. However, when I do it this way, the calculator gives me an equation for x, an equation for y, and 2 equations for z, and no equation for s. I am not sure what I am doing wrong. Is there some other way to do this that would yield me 4 equations, one for each variable I want to solve for in terms of V?
If my method for solving linear equations is confusing in any way, I basically followed this video
http://www.youtube.com/watch?v=z802L29JyQE
Thanks in advance.
Solved! Go to Solution.
Accepted Solutions
05-31-2014 05:25 PM
Hi,
Not sure exactly how you're entering it, so I'm being explicit just to b certain:
Notes:
1) as an equation is being entered, use ' '
2) it is better to use a comma to separate real and imaginary parts
3) use explicit multiply
so the entry will look like:
'(4,3*X)=(4,7)'
For this simple equation and assuming X is defined as the independent variable (shown as 'X' in the middle top of the screen), you can use SOLVEVX for this one: (no. 5 in S.SLV menu or F5 if using soft-keys)
with "_Approx" unchecked the answer is:
X=7/3
with "vApprox" checked the answer is:
X=(2.333333333,0) (although X is part of the imaginary number, it itself is a real number).
Regards.
_________________________________________________________
calculator enthusiast
04-23-2014 07:35 AM
Hi,
Try using SOLVE instead (in the S.SLV menu (White LeftShift 7), choose "6. Solve" or F6 if using soft menus).
Also see Chapter 7 of the 887-page HP-50G User's Guide.
Original arrays:
Solutions using SOLVE:
Hope this helps.
_________________________________________________________
calculator enthusiast
04-23-2014 04:10 PM
Hi!, rbridges:
Welcome, to Forum!.
Please, try with this examples ... http://50gtutorials.blogspot.com.ar/2009/10/solving-systems-of-equations-on-hp-50g.html
Have a nice day !.
@Maké (Technical Advisor Premium - HP Program Top Contributor).
Provost in HP Spanish Public Forum ... https://h30467.www3.hp.com/
05-30-2014 05:02 PM
Hi,
In settings MODE -> CAS make sure "_Numeric" and "_Approx" are both UNchecked (otherwise the solver searches for numeric only solution, but you require a symbolic solution containing V).
Side note: you probably noticed I had my setting in "Vertical vector display" mode. Hope it didn't confuse you (it is set with MODE -> Flags and check 98).
Hope this helps.
_________________________________________________________
calculator enthusiast
05-31-2014 03:31 PM
Hey Bart.
Thanks so much. That worked for me!
Now while I have your attention I figured I would try to ask one more question if I may.
I am now trying to solve equations with complex variables in them. This following example is much more simple than the types of equations I am trying to solve, but it highlights the problem I am having:
4 + j3x = 4 + j7
To solve this simple equation for x by hand, one would simply set 3x = 7 and solve for x. This would give x = 2.3333
When I attempt to enter the left hand side of this equation on the HP50g, I do the following
1. open parenthesis
2. 4 SPACE 3x
3. enter
And then the calculator gives me a syntax error at the "x"
The calculator doesn't seem to like when I try to enter variables inside of the complex number.
How could I go about solving something like this?
05-31-2014 05:25 PM
Hi,
Not sure exactly how you're entering it, so I'm being explicit just to b certain:
Notes:
1) as an equation is being entered, use ' '
2) it is better to use a comma to separate real and imaginary parts
3) use explicit multiply
so the entry will look like:
'(4,3*X)=(4,7)'
For this simple equation and assuming X is defined as the independent variable (shown as 'X' in the middle top of the screen), you can use SOLVEVX for this one: (no. 5 in S.SLV menu or F5 if using soft-keys)
with "_Approx" unchecked the answer is:
X=7/3
with "vApprox" checked the answer is:
X=(2.333333333,0) (although X is part of the imaginary number, it itself is a real number).
Regards.
_________________________________________________________
calculator enthusiast
