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May
4
comment Why doesn't $ \lim_{(x,y)\rightarrow(0,0)} xy\sin(\frac{1}{xy}) $ exist?
How to know when it's ok to take such $z$? or polar coordinates?
May
4
accepted Why doesn't $ \lim_{(x,y)\rightarrow(0,0)} xy\sin(\frac{1}{xy}) $ exist?
May
4
asked Why doesn't $ \lim_{(x,y)\rightarrow(0,0)} xy\sin(\frac{1}{xy}) $ exist?
Apr
30
awarded Custodian
Apr
30
revised Find all functions $F(x,y)$ such as $\frac{\sqrt{3}}{2}\frac{\partial{f}}{\partial{x}}+\frac{1}{2}\frac{\partial{f}}{\partial{y}}=0$
added 8 characters in body; edited title
Apr
30
reviewed Approve suggested edit on Find all functions $F(x,y)$ such as $\frac{\sqrt{3}}{2}\frac{\partial{f}}{\partial{x}}+\frac{1}{2}\frac{\partial{f}}{\partial{y}}=0$
Apr
30
asked Find all functions $F(x,y)$ such as $\frac{\sqrt{3}}{2}\frac{\partial{f}}{\partial{x}}+\frac{1}{2}\frac{\partial{f}}{\partial{y}}=0$
Apr
17
comment How to integrate a vector function in spherical coordinates?
Thanks! much clearer now
Apr
17
accepted How to integrate a vector function in spherical coordinates?
Apr
17
awarded Commentator
Apr
17
comment How to integrate a vector function in spherical coordinates?
How would you express $\hat{r}$ without converting back to cartesian coordinates?
Apr
17
comment How to integrate a vector function in spherical coordinates?
But each coordinate should be independent on the other? no?
Apr
16
asked How to integrate a vector function in spherical coordinates?
Mar
14
awarded Supporter
Mar
10
awarded Notable Question
Mar
1
comment Let $T$ be a Hermitian operator and $\|v\|=1$, prove $\langle T^2(v),v\rangle \ge\langle T(v),v\rangle^2$
I removed the hint from the question, thanks
Mar
1
revised Let $T$ be a Hermitian operator and $\|v\|=1$, prove $\langle T^2(v),v\rangle \ge\langle T(v),v\rangle^2$
hint was wrong...
Mar
1
comment Let $T$ be a Hermitian operator and $\|v\|=1$, prove $\langle T^2(v),v\rangle \ge\langle T(v),v\rangle^2$
Oh well... after reading your answer I was under the impression that the hint is wrong. I received it in a test :(
Mar
1
comment Let $T$ be a Hermitian operator and $\|v\|=1$, prove $\langle T^2(v),v\rangle \ge\langle T(v),v\rangle^2$
I finally understand it, I accepted your answer. I would still like to know how to prove/use the hint
Mar
1
accepted Let $T$ be a Hermitian operator and $\|v\|=1$, prove $\langle T^2(v),v\rangle \ge\langle T(v),v\rangle^2$
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