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4h
reviewed Reject Is 9 + 10 actually equal to 21?
Dec
15
revised Vertex-transitive graphs and deletion of vertices
added citation
Dec
12
reviewed Approve 4 vehicles Probability that any three of them are operational at one time
Dec
12
answered Vertex-transitive graphs and deletion of vertices
Dec
11
reviewed Approve Getting the ratio that an oriented segment is divided by a line
Dec
11
reviewed Approve galois-representations tag wiki
Dec
10
reviewed Approve Proof using the epsilon delta definition
Dec
9
answered What is the multiplicity of the largest eigenvalue of a graph?
Dec
8
awarded  Caucus
Dec
8
reviewed Approve Prove the equality that $4x^{4} + 4y^{3} + 5x^{2} + y + 1$ >or equal to $12xy$ if $x$ and $y$ are real and positive
Dec
1
comment characteristic polynomial of adjacency matrix of join of two graph.
It's Theorem 2.7 in the first edition of CDS.
Nov
30
comment characteristic polynomial of adjacency matrix of join of two graph.
I am pretty sure you will find this explicitly in Cvetkovic, Doob and Sachs "Graph Spectra". (My copy's out of reach right now.)
Nov
30
reviewed Edit Using the Definition of derivative to derive the derivative of a function
Nov
30
revised Using the Definition of derivative to derive the derivative of a function
improved formatting, grammar
Nov
29
reviewed Approve Findin the $\sup$ and $\inf$ of defined sets
Nov
29
reviewed Approve Prove that there is no number that divides both n and n+1
Nov
29
reviewed Approve Quadratic Program reformulation
Nov
29
reviewed Approve Prove that there is no number that divides both n and n+1
Nov
27
comment Why this graph has automorphism group is isomorphic to the cyclic group of order 4?
@Babak Miraftab: You also need to show that any automorphism that fixes each of the four vertices of degree five is trivial, and even then you only get that the automorphism group is a subgroup of the symmetric group on four points.
Nov
26
comment New proof about normal matrix is diagonalizable.
@John Hughes: do you mean "unitarily similar" here?