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location Ann Arbor, MI
age 25
visits member for 4 years
seen 9 hours ago

Grad student at Michigan.


1d
reviewed Approve suggested edit on Is there an injective function such that $f(x^2)-f^2(x)\ge \frac{1}{4}$?
Aug
10
awarded  Yearling
Jul
2
comment When is $M \times N$ contained in$ M \otimes_{R} N$.
Should be $M = N = 0$.
Jun
29
answered Express Norm Using Inner Product
Jun
6
comment For $a=\cos(2\pi/n)$, show that $[\mathbb{Q}(a):\mathbb{Q}] = \ldots$
If $\zeta = e^{2 \pi i / n}$, can you think of a way to express $a$ in terms of $\zeta$? Remembering the complex definition of cosine might be useful here...
May
28
comment Show $\mathbb{Q}(\zeta)$ does not contain $\sqrt{7}$
Yes, but I'm not sure what motivation there is to not use Galois theory. Since you originally had the algebraic-number-theory tag, you could use that 2 is unramified in $\mathbf{Q}(\zeta_7)$.
May
28
revised Show $\mathbb{Q}(\zeta)$ does not contain $\sqrt{7}$
edited tags
May
28
comment Show $\mathbb{Q}(\zeta)$ does not contain $\sqrt{7}$
Do you know what $\mathrm{Gal}(\mathbf{Q}(\zeta)/\mathbf{Q})$ is?
May
27
reviewed Edit suggested edit on Field $K (x)$ of rational functions over $K$, the element $x$ has no $p$th root.
May
27
revised Field $K (x)$ of rational functions over $K$, the element $x$ has no $p$th root.
improved formatting
Apr
27
comment How is this function continuous?
The book does not say that the domain of the function is $\mathbf{R}$, but rather implies that it is $[0,1] \cup [2,3]$, in which case the function is continuous.
Apr
27
comment How is this function continuous?
@OscarFlores Can you give us a reference to which textbook this came from?
Apr
25
comment Finding an orthogonal $P$ and a diagonal matrix $D$ so that $D=P^tAP$
You can do this if and only if $A$ is (real) symmetric.
Apr
20
answered $\Bbb Z[i\alpha]$ UFD's
Apr
3
reviewed Close The trace as an integral over a sphere
Apr
3
reviewed Close What is the sum of $\sum\limits_{n = 1}^\infty {\arctan \dfrac{2}{{{n^2}}}}$ and why?
Apr
3
reviewed Close What is the probability of winning the game “one,two,three”?
Apr
3
reviewed Leave Open $\lim_{n→∞} f(n+x)=0$ results in $ \lim_{x→∞} f(x)=0$
Apr
3
reviewed Leave Open the rank of a matrix and its inverse are always equal
Apr
3
reviewed Leave Open Algebra Question ( possible values)