# Math Help - Algebraic Structures Matrix

1. ## Algebraic Structures Matrix

I really need help, i need to investigate the properties of the set of matrices
a -b
b a :a,b belongs to real numbers

I need to know
• transformation properties
• diagonalisation
• group properties
• subgroups
• Isomorphism
Any help would be fantastic!

thanks!

2. You will have to be more specific than that to get useful answers. For the second part, I dont think you can diagonalize it(over reals) since its eigenvalues are always complex.

What transformational property do you want? What group, subgroup properties are you looking at?

3. I think that is why i am having the problem! That is exactly how the question is worded no extra information is given.

4. Hello,

Originally Posted by mrks1d
I think that is why i am having the problem! That is exactly how the question is worded no extra information is given.
But it's not a problem to diagonalise it over $\mathbb{C}$ o.O
The eigenvectors will remain over $\mathbb{R}$

$\chi_A(\lambda)=(a-\lambda)^2+b^2=(a-\lambda-ib)(a-\lambda+ib)$

$\lambda_1=a+ib$
$\lambda_2=a-ib$

Then find the eigenvectors. To solve for X(x,y), representing the eigenvector, just remember that if a complex number is null, it means that its real part is zero and its imaginary part is zero..