1,104 reputation
625
bio website math.stackexchange.com/users/…
location Antarctica
age 78
visits member for 1 year, 9 months
seen Jan 31 at 5:07

Self-learning mathematics. Many thanks to those who make time to help others on the site.


May
29
asked Showing existence of an element with order $p$
May
28
revised Puzzle at Adobe Interview
changed from all caps
May
28
suggested suggested edit on Puzzle at Adobe Interview
May
27
accepted Proving $\sum_{m=0}^M \binom{m+k}{k} = \binom{k+M+1}{k+1}$
May
27
comment Proving $\sum_{m=0}^M \binom{m+k}{k} = \binom{k+M+1}{k+1}$
but $r$ is indexed
May
27
comment Proving $\sum_{m=0}^M \binom{m+k}{k} = \binom{k+M+1}{k+1}$
In my text, I have an identity $\sum_{r\geq 0} \binom{r + n}{r} x^r = 1/(1-x)^{n+1}$ This may be the cause of my confusion, but is this identity correct and is it equivalent to the one you used?
May
27
comment Proving $\sum_{m=0}^M \binom{m+k}{k} = \binom{k+M+1}{k+1}$
Is there a typo in the second equation (first sum)? I believe $k$ should be indexed.
May
26
comment Finding the values of $z$ s.t. $\sum_{n=0}^{\infty} \left( \frac{z}{1+z} \right)^n$ is convergent
yeah, I got the same thing, but I just didn't express the final step like that. Does it matter though?
May
26
accepted Finding the values of $z$ s.t. $\sum_{n=0}^{\infty} \left( \frac{z}{1+z} \right)^n$ is convergent
May
26
comment Finding the values of $z$ s.t. $\sum_{n=0}^{\infty} \left( \frac{z}{1+z} \right)^n$ is convergent
$z > 1-\bar{z}$?
May
26
revised Finding the values of $z$ s.t. $\sum_{n=0}^{\infty} \left( \frac{z}{1+z} \right)^n$ is convergent
edited tags
May
26
asked Finding the values of $z$ s.t. $\sum_{n=0}^{\infty} \left( \frac{z}{1+z} \right)^n$ is convergent
May
22
asked Proving $\sum_{m=0}^M \binom{m+k}{k} = \binom{k+M+1}{k+1}$
May
19
awarded  Constituent
May
19
asked Proving that $X$ is a subgroup of $G$
May
19
accepted Definition of open set/metric space
May
18
asked Definition of open set/metric space
May
17
comment Are there any series whose convergence is unknown?
Out of curiosity, what makes this a "joke" answer?
May
15
accepted Finding asymptotes to general functions
May
15
asked Finding asymptotes to general functions