Determinant exercise: show that

In summary: Maybe try refreshing the page or using a different device. The link is to a picture of a math problem involving determinants and an explanation for solving it using induction. In summary, the conversation is about solving a math problem using induction and attaching a picture to help explain the solution.
  • #1
Alistair Over
3
0
Hey people, could someone solve this problem and explain step by step? It's from a past exame and I really need to know how to do it, tried everything I know (not much tho). Please don't omit steps.Really appreciated!
imageshack.us/photo/my-images/403/dvidafrumdelgebra.png/
 
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  • #2
Alistair Over said:
Hey people, could someone solve this problem and explain step by step? It's from a past exame and I really need to know how to do it, tried everything I know (not much tho). Please don't omit steps.Really appreciated!
imageshack.us/photo/my-images/403/dvidafrumdelgebra.png/

Your link does not load. Generally, though, what you are asking here violates the PF rules. You are supposed to show us your work first, then ask for help.

RGV
 
  • #3
Just attach the picture directly to your own post. No need to use external image hosting sites.
 
  • #4
Alistair Over said:
Hey people, could someone solve this problem and explain step by step? It's from a past exame and I really need to know how to do it, tried everything I know (not much tho). Please don't omit steps.Really appreciated!
imageshack.us/photo/my-images/403/dvidafrumdelgebra.png/

I think you can try finding an expression for each element of ##A_n## first. Let us call it ##x_{ijn}##

$$ x_{ijn}=(a-b)\delta_{ij}+b $$
$$ x_{ijn}=a\delta_{ij}+(1-\delta_{ij})b $$

Then you can somehow show the result. Not sure how you can continue though.
 
  • #5
here is the atachment! Sorry but I have my examination tomorrow, I'm desesperate :s
 

Attachments

  • Dúvida fórum de álgebra.png
    Dúvida fórum de álgebra.png
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  • #6
Proof by induction- if you expand each determinant, [itex]A_{n+1}[/itex], by the first row, you get a times [itex]A_n[/itex]+ n-1 times b times a subdeterminant.
 
  • #7
Ray Vickson said:
Your link does not load.

It does for me.
 

FAQ: Determinant exercise: show that

What is the purpose of determinant exercise?

The purpose of determinant exercise is to demonstrate the properties and calculations of a determinant, which is a mathematical tool used to solve systems of linear equations and find the area or volume of geometric shapes.

How do you show that a matrix has a non-zero determinant?

To show that a matrix has a non-zero determinant, you can use the following steps:1. Expand the matrix using the Laplace expansion method.2. Simplify the resulting expression.3. If the resulting expression is non-zero, then the matrix has a non-zero determinant.

What is the relationship between the determinant and the inverse of a matrix?

The determinant and the inverse of a matrix are closely related. The determinant of a matrix is equal to 1 divided by the determinant of its inverse. In other words, the determinant of a matrix A is equal to 1/det(A-1).

Can the determinant of a matrix be negative?

Yes, the determinant of a matrix can be negative. The sign of the determinant depends on the number of row swaps that are performed during the calculation. If an odd number of row swaps are performed, the determinant will be negative. If an even number of row swaps are performed, the determinant will be positive.

What are the applications of determinant in real life?

Determinants have various applications in real life, including:1. Solving systems of linear equations in fields such as engineering and economics.2. Finding the area or volume of geometric shapes in fields such as architecture and physics.3. Calculating the probability of events in statistics.4. Solving optimization problems in computer science and operations research.

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