2,794 reputation
413
bio website
location
age
visits member for 3 years, 9 months
seen 17 hours ago

19h
answered Periodic Functions
22h
comment Periodic Functions
hint: you ask for a number $T$ such that for all $x$ $$ \sin(2(x+T)+3)=\sin(2x+3+2T) =^? \sin(2x+3) $$
1d
comment $\Bbb{R}^2$ not homeomorphic to $\Bbb{R}^2\setminus \{0\}$
en.wikipedia.org/wiki/End_%28topology%29 might be helpful?
1d
comment Proof of Vector Space Axioms
Or do you want to proof that the axioms hold for a certain example ($k^n$)?
2d
answered Finding $ \dfrac{\partial z}{\partial x} \text{and}\dfrac{\partial z}{\partial y} $ if $ F(cx - az, cy-bz) = 0 $
2d
comment Prove the length of a linear combination of an orthonormal basis
Try the case $p=2$
Nov
19
answered Prove the length of a linear combination of an orthonormal basis
Nov
19
answered Homeomorphism from $O(n)/(O(1)\times O(n-1))$ to $S^{n-1}/\tilde{}$
Nov
19
answered Homomorphism preserves normality
Nov
19
revised Is $\sqrt2$ a tricky notation?
added 277 characters in body
Nov
19
answered Is $\sqrt2$ a tricky notation?
Nov
17
answered $\sqrt{ab} = \sqrt{a} \sqrt{b}$
Nov
12
comment How to prove that $S^{2n+1}/S^1$ is homeomorphic to $\mathbb CP^n$ under a given identification
Yeah, I forgot. It is a quotient map...then a continous bijection between a compact space and ...
Nov
12
answered How to prove that $S^{2n+1}/S^1$ is homeomorphic to $\mathbb CP^n$ under a given identification
Nov
7
comment Complex Power Series Convergence and Expansion
move everything to $0$ ($u=z-1$). What do you know about power series (radius of convergence..if it converges at u=2 then...)
Nov
6
comment Why is it important to extend the trigonometric functions to all angles?
Yes. You may also think about wave phenomena.
Nov
6
comment Why is it important to extend the trigonometric functions to all angles?
You might want to model a pendulum or any other oscillator $$ x(t)=A \sin(\omega t) $$, and this thing doesn't stop after a time $T$
Oct
28
answered What is the relation between $a$ and $b$?
Oct
28
comment What is the relation between $a$ and $b$?
$p$ divides $a$ if and only if $p$ divides $b$ - there is nothing more to say, I wouldn't call this a "relation"
Oct
24
answered Why does 2^-2 equal 1/2^2?