Kirchhoff's Law: Solving Matrix Inverse on HP 48GX

In summary, the conversation discusses a problem with using Kirchhoff's Law and a 3x3 matrix with voltage values. The person is having trouble taking the inverse of the first equation on their HP 48GX calculator and wonders if it is possible to convert a decemile into a fraction. They later realize their mistake and solve the problem.
  • #1
nightwing
4
0
This is more of a calculator problem, we are currently doing Kirchhoff's Law in class and we are using the equation [A]^-1 x [X], where A is a 3x3 matrix containing the I3=I1+I2 and the V Rise and V Drop equations and the X is a matrix of the voltage values.
Ex.(I1)=(I2)+(I3) Loop 1= 12=(I1)5+(I2)4+10 Loop 2= (I3)2=10+(I2)4
0=-I1+I2+I3 0=(I1)5+(I2)4+10-12 0=10+(I2)4-(I3)2
[[-1 1 1] ^-1 [[ 0 ]
[ 5 4 0] x [ 2 ]
[ 0 4 -2]] [-10]]
But herein lies my problem, I have an HP 48GX, and it will not allow me to take the inverse of the first equation. I tried to take the inverse of each individual number as i entered it into the matrix, but the answer that i derived was not the same as those of my fellow classmates, all of whom are using TI 3600's. So how would i go about fixing this problem. And on a smaller note, is it possible to convert a decemile into a fraction? Thanx.
 
Engineering news on Phys.org
  • #2
never mind, i just had to stop being a moron
 
  • #3


It seems that you are having trouble taking the inverse of the matrix [A] in the equation [A]^-1 x [X]. This could be due to the limitations of your calculator, as HP 48GX may not have the feature to directly calculate matrix inverses. In this case, you can try using the inverse function of the individual numbers as you enter them into the matrix, but this may not give you the exact same answer as your classmates who are using TI 3600's.

One way to fix this problem is to manually calculate the inverse of [A] using the Gauss-Jordan method or any other method of matrix inversion. This will give you the exact inverse of [A] and you can then proceed with the rest of the calculations.

As for converting decemiles to fractions, it is possible to do so by converting the decemile to a decimal and then converting the decimal to a fraction. For example, if you have 0.5 decemiles, you can convert it to 0.05 and then to 1/20. You can use your calculator to simplify the fraction if needed.
 

1. What is Kirchhoff's Law and how does it apply to matrix inverse on the HP 48GX?

Kirchhoff's Law, also known as Kirchhoff's Circuit Law, states that the sum of currents entering a node in an electrical circuit is equal to the sum of currents leaving the node. This law is applicable to matrix inverse on the HP 48GX because it helps us determine the flow of current, or in this case, the flow of data, in a matrix inversion process.

2. Why is it important to use Kirchhoff's Law when solving matrix inverse on the HP 48GX?

Kirchhoff's Law is important to use when solving matrix inverse on the HP 48GX because it ensures that all the necessary data is accounted for and properly calculated. It helps us avoid errors and ensures that the inverse of the matrix is calculated accurately.

3. How can Kirchhoff's Law be applied to solve matrix inverse on the HP 48GX?

Kirchhoff's Law can be applied to solve matrix inverse on the HP 48GX by breaking down the matrix into smaller components and applying the law to each component. This allows us to determine the flow of data and calculate the inverse of the matrix step by step.

4. Are there any limitations to using Kirchhoff's Law for solving matrix inverse on the HP 48GX?

Yes, there are some limitations to using Kirchhoff's Law for solving matrix inverse on the HP 48GX. It may not work for matrices with a large number of variables or for matrices that are not properly structured. In these cases, alternative methods may need to be used.

5. Can Kirchhoff's Law be used for other types of calculations on the HP 48GX?

Yes, Kirchhoff's Law can be applied to other types of calculations on the HP 48GX, such as solving systems of linear equations or finding determinants of matrices. It is a useful tool in many mathematical processes and can be adapted for various calculations.

Similar threads

  • Introductory Physics Homework Help
Replies
1
Views
633
  • Introductory Physics Homework Help
Replies
9
Views
1K
  • Introductory Physics Homework Help
Replies
9
Views
2K
  • Introductory Physics Homework Help
Replies
22
Views
2K
  • Introductory Physics Homework Help
Replies
12
Views
1K
  • Engineering and Comp Sci Homework Help
Replies
7
Views
1K
  • Introductory Physics Homework Help
Replies
18
Views
1K
  • Introductory Physics Homework Help
Replies
16
Views
892
  • Engineering and Comp Sci Homework Help
Replies
26
Views
2K
  • Introductory Physics Homework Help
Replies
10
Views
1K
Back
Top