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1d
comment Supplementary in $M_n(\mathbb{K})$
This is only true if $\operatorname{char}(K)$ does not divide $n$, otherwise $\operatorname{Tr}(\lambda I_n)=n\lambda=0$ in $K$. What will always work is the space $\{\lambda E_11 | \lambda\in K\}$.
1d
reviewed Leave Closed Sharing items to a particular number of people
Aug
22
comment An endomorphism $f$ such that $f\circ f=1$
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Aug
22
comment “If $A$ is a good matrix then $A^TA$ is even better”
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Aug
22
comment Short exact sequence and extension
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Aug
22
reviewed Leave Open Why is this sum well-defined?
Aug
22
reviewed Close Can you explain to me why we need Limits at all?
Aug
22
reviewed Close How many people are needed in a team to ensure one is at work?
Aug
22
reviewed Close Recommend a book for complex analysis.
Aug
22
comment dual algebra of a coalgebra
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Aug
22
reviewed Close $D\det_A$ exists and equals $D\det_A (H)=\det (A) \operatorname{trace} (A^{-1}H) $?
Aug
22
reviewed Close $y''+x^2y=0, y=u\sqrt{x}, z=(\frac{1}{2})(x^2)$
Aug
22
reviewed Leave Open Calculus Paradox. I mean, what's wrong with what I think?
Aug
22
reviewed Close Integrating $\frac{1}{(x^4 -1)^2}$
Aug
22
reviewed Leave Open Polynomial Interpolation and Security
Aug
22
reviewed Reopen Considering only integers, answer the following questions:
Aug
22
reviewed Leave Closed Is an algorithm to find all primes up to $n$ that runs in $O(n)$ time fast?
Aug
22
comment Every group is isomorphic to a group of permutations?
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Aug
22
comment Units and zero divisors in $\mathbb{Z_2[x]}/(x^2 + 1)$ and in general
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Aug
22
comment if $A$, $B$ and $A+B$ are nilpotent matrices over $\mathbb{F}$, then $\mathrm{tr}(AB)=0$ .
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