Reputation
2,592
Top tag
Next privilege 3,000 Rep.
Cast close and reopen votes
Badges
9 27
Newest
 Yearling
Impact
~79k people reached

Apr
14
revised School Survey percentage problem
deleted 7 characters in body
Apr
14
answered School Survey percentage problem
Apr
14
comment School Survey percentage problem
General tip: First I would ignore contemplating the options; they are merely the answer. Try to work out how you get the answer from the data presented in the question. Read through the question and when you find a new piece of information, jot it down in short hand (use maths symbols). The information you jotted down is what you work with to get the answer.
Apr
13
comment Calculate $\int_\Gamma ze^{z}dz$ where $\Gamma$ is line from point $z_1=0$ to point $z_2=\frac{\pi i}{2}$
@user227317 yes. See my answer for full details, but you got the answer! You can also use Blatter's approach too.
Apr
13
answered Calculate $\int_\Gamma ze^{z}dz$ where $\Gamma$ is line from point $z_1=0$ to point $z_2=\frac{\pi i}{2}$
Apr
12
comment Calculate $\int_\Gamma ze^{z}dz$ where $\Gamma$ is line from point $z_1=0$ to point $z_2=\frac{\pi i}{2}$
@user227317 no, as I said use the substitution $z=it$. Also @ JessicaK's solution will also work. See also @ ChrisrianBlatter's answer.
Apr
12
comment Calculate $\int_\Gamma ze^{z}dz$ where $\Gamma$ is line from point $z_1=0$ to point $z_2=\frac{\pi i}{2}$
You need to parametrize the curve $\Gamma$, e.g. let $z(t)=it$ where $t\in[0,\pi/2]$. Looks like integration by parts may be helpful too.
Apr
11
revised Calculating the lie algebra of $SO(2,1)$
added 1 character in body
Apr
8
comment $F(x)+G(y)= e^{x+y}?$
Yes, the way it is written confused me for a moment. However, on expanding the middle equality now I clearly see it does equal $F(1)-F(0)$. I was looking at what you had written from a different perspective - I was trying to construct the middle equality from the first by rearranging the original equation. Sorted now I see clearly what's happing - that "old trick" of adding something and then taking it away, so yes maybe best read right to left. +1 for your answer!
Apr
8
comment $F(x)+G(y)= e^{x+y}?$
I could be wrong, but shouldn't the middle equality be $-G(y)+e^{1+y}-(-G(y)+e^y)$ ? Maybe it's equivalent...
Apr
8
revised How to deduce that $1\cdot 1 + 2\cdot 1 + 2\cdot 2 + 3\cdot 1+3\cdot 2+3\cdot 3 +…+(n\cdot n) = n(n+1)(n+2)(3n+1)/24$
edited title
Apr
8
revised How to deduce that $1\cdot 1 + 2\cdot 1 + 2\cdot 2 + 3\cdot 1+3\cdot 2+3\cdot 3 +…+(n\cdot n) = n(n+1)(n+2)(3n+1)/24$
added 18 characters in body
Apr
8
comment How to deduce that $1\cdot 1 + 2\cdot 1 + 2\cdot 2 + 3\cdot 1+3\cdot 2+3\cdot 3 +…+(n\cdot n) = n(n+1)(n+2)(3n+1)/24$
Try proof by induction ?
Apr
6
revised Solving $z=w/2-\sin(tw)/(2t)$ for $w$
deleted 140 characters in body
Apr
4
accepted Solving $z=w/2-\sin(tw)/(2t)$ for $w$
Apr
4
reviewed Approve Solving $z=w/2-\sin(tw)/(2t)$ for $w$
Apr
4
asked Solving $z=w/2-\sin(tw)/(2t)$ for $w$
Apr
2
accepted Question on branches and $\iff$.
Mar
30
comment Question on branches and $\iff$.
Thank you. So if I restrict my attention to the principal branch (and I will also assume $f$ and $g$ are continuous) then $f+ig=0\iff e^{f(x)}\cos(g(x))+ie^{f(x)}\sin(g(x))=1$ ?
Mar
30
revised Question on branches and $\iff$.
added 68 characters in body