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2d
answered Show that $B$ is invertible if $B=A^2-2A+2I$ and $A^3=2I$
2d
comment Chinese Remainder Theorem example
The program's solution is wrong; 1066 doesn't work mod 52.
2d
comment Chinese Remainder Theorem example
@A.P. It seems clear that he's asking some subset of the following: "Is there a solution to the problem I gave? Is 1066 a solution? Does my code work?"
2d
comment Eigenvalues of $A=\begin{bmatrix}2&1\\\alpha&0\end{bmatrix}$
Actually, it is not clear from the phrasing of the question whether $\alpha$ is allowed to be complex. That being said, it wouldn't affect your answer.
2d
comment Eigenvalues of $A=\begin{bmatrix}2&1\\\alpha&0\end{bmatrix}$
The way in which you expressed the eigenvalues is correct, and valid whether or not the roots are real. In $\Bbb C$ means "including complex roots".
Jul
28
awarded  Nice Answer
Jul
28
comment Are $A$ and $A^\top$ similar?
Perhaps it helps to note that $$ \{S: SA - A^TS = 0\} $$ is a linear subspace
Jul
28
comment Are $A$ and $A^\top$ similar?
You mean that a suitable $S$ with entries in $K$ exists. Yes, it is necessary to make that observation.
Jul
28
comment Practice Exam question need help!
Do you know the formula for the projection on a space?
Jul
28
comment $\left\| A \right\| \le \varepsilon \Rightarrow \left\| {\mathop A\limits^{\_\_} } \right\| \le \varepsilon$
@A.G. Thank you!
Jul
28
revised $\left\| A \right\| \le \varepsilon \Rightarrow \left\| {\mathop A\limits^{\_\_} } \right\| \le \varepsilon$
added 4 characters in body
Jul
28
revised $\left\| A \right\| \le \varepsilon \Rightarrow \left\| {\mathop A\limits^{\_\_} } \right\| \le \varepsilon$
added 7 characters in body
Jul
28
answered Are $A$ and $A^\top$ similar?
Jul
28
answered $A$ is a symmetric postivie definite matrix. Prove that $A^k$ is also a positive deinite
Jul
28
answered $\left\| A \right\| \le \varepsilon \Rightarrow \left\| {\mathop A\limits^{\_\_} } \right\| \le \varepsilon$
Jul
28
answered Prove that $\lim_\limits{x\to 0}{f(x)}=0$
Jul
27
awarded  Enlightened
Jul
27
awarded  Nice Answer
Jul
27
revised Eigenspace and $\ker(T)$
added 16 characters in body
Jul
27
comment Find bounded function satisfying f(0)=0, f'(0)=0, and bounded first and second derivatives
@Nemo and what would $f'(0)$ be, then?