
Multiplication by identity matrix - Mathematics Stack Exchange
Sep 28, 2019 · Yes, this is why it is called the identity matrix. Any matrix multiplied by the identity matrix is the original matrix, just as the multiplicative identity for $\mathbb {R}$ is $1$.
Identity matrix and its relation to eigenvalues and eigenvectors
Any vector subject to the identity matrix will give you the same vector back. That is the property of the identity matrix. But in light of eigenvectors and eigenvalues, this also matches the situation for …
How does adding the identity matrix to a square matrix change the ...
How does adding the identity matrix to a square matrix change the determinant? Ask Question Asked 13 years ago Modified 9 months ago
Proof verification for Identity matrices - Mathematics Stack Exchange
Nov 30, 2018 · 2 Furthermore if you want a concrete example of a matrix whose square is the identity but not itself a simple matrix consider for example this one: $$\begin {bmatrix}\frac {1} {2} & \frac {3} …
Standard Matrix vs. Identity Matrix - Mathematics Stack Exchange
May 16, 2018 · Is there a difference between identity and standard matrices? Or are they are just different notations to distinguish between regular matrices and linear transformations?
linear algebra - If $A^2 = I$ (Identity Matrix) then $A = \pm I ...
Every matrix satisfying $A^2=I$ is diagonalizable, because either it is $\pm I$ or its minimal polynomial is $ (x-1) (x+1)$. The general solution is obtained by taking all diagonal matrices with entries $\pm 1$ …
linear algebra - Number of matrices whose square is identity ...
Oct 23, 2012 · I assumed matrices over $\mathbb {R}$. The connection to other fields is relatively straightforward, though I can elaborate if needed.
What is the meaning of subtracting from the identity matrix?
Jun 13, 2016 · What is the meaning of subtracting from the identity matrix? Ask Question Asked 9 years, 6 months ago Modified 5 years, 1 month ago
Is $A$ the $2 × 2$ identity matrix? - Mathematics Stack Exchange
Jun 27, 2019 · If $A$ is a $2 × 2$ complex matrix that is invertible and diagonalizable, and such that $A$ and $A^2$ have the same characteristic polynomial, then $A$ is the $2 × 2$ identity matrix.
Determinant of the Identity Matrix proof - Mathematics Stack Exchange
Apr 23, 2016 · Determinant of the Identity Matrix proof Ask Question Asked 9 years, 8 months ago Modified 9 years, 8 months ago