Reputation
2,213
Top tag
Next privilege 2,500 Rep.
Create tag synonyms
Badges
7 15
Newest
 Yearling
Impact
~22k people reached

Mar
17
revised Relation between vertices and edges in a tree?
added 10 characters in body
Mar
17
comment Relation between vertices and edges in a tree?
And less than $n-1$ edges is not possible if you require the graph to be connected
Jan
13
comment Matrix multipication
If $\omega^4 \neq 1$ we get $1 = b\omega^3 = \omega \omega^3 = \omega^4$, a contradiction. So if $\omega^4 \neq 1$ there are no solutions.
Jan
13
comment Matrix multipication
What do you get when you plug those values back in? Remember, $\omega^4$ is $1$, otherwise there are no solutions
Jan
13
comment Matrix multipication
Can't you just compare the entries in the first and last matrix? Then $a=1$, $b=\omega$, $c=\omega^2$ and $d=\omega^3$, leaving us with $1=\omega^4 = \omega^8 = \omega^{12}$ (from the last row). So $\omega$ has to be a fourth root of unity.
Dec
1
reviewed Approve Limit of function, when $x$ approaches $a$
Dec
1
comment Limit of function, when $x$ approaches $a$
Well as you already said, the limit is equal to the derivate of $\ln(x)$ at the point $a$. You know that the derivate is $\frac 1 x$, so the limit is equal to $\frac 1 a$.
Dec
1
reviewed Approve Evaluating $\int_0^2 x(8-x^3)^{\frac{1}{3}}\ dx$
Jul
20
awarded  Yearling
Jun
6
reviewed Approve Solution of an equation and a system of inequalities
May
14
reviewed Approve substraction of groups in direct sum
May
12
comment Question about principle ideals and polynomials and quotient ring construction?
You are taking the ideal $<x^2+1>$ in $R[X]$, thus $<x^2+1> = \{ p\in R[X] | p = gf, g \in R[X]\}$. So it is every possible polynomial multiple of $x^2+1$.
May
12
answered A complex variable function integrated over an infinitesimal disk
May
10
reviewed Approve Evaluating the Legendre symbol $\left(\frac{5}{p}\right)$ using Gauss's lemma instead of quadratic reciprocity.
May
10
reviewed Approve How do you take the derivative of a variable with respect to a different variable:
May
10
reviewed Approve Probability of having k defined elements while choosing m elements from a set of N
May
10
reviewed Approve A curious compactness confusion: space filling curves in the hilbert cube that contradict a bona fide theorem?
May
10
reviewed Approve Complex numbers equivalence proof
May
9
reviewed Approve Topology: Example of a compact set but its closure not compact
May
8
reviewed Reject Calculating normalization constant in circle detection process