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bio website linkedin.com/in/gt6989b
location New York, NY
age 35
visits member for 2 years, 7 months
seen 9 hours ago

Feb
20
comment How to take slope of tangent line which passes through the origin
@mcihak changed it, this is the only case where it makes sense.
Feb
20
revised How to take slope of tangent line which passes through the origin
added 7 characters in body
Feb
19
comment Proving that if $a^2+b^2=c^2$ for $a,b,c \in \Bbb Z^+$, then either $a$ or $b$ is even.
Another lemma you may need is that if $a$ is odd, then $a^2$ is odd, but it is trivial since $(2k+1)^2 = 4k^2+4k+1$ which is clearly odd...
Feb
19
comment Proving that if $a^2+b^2=c^2$ for $a,b,c \in \Bbb Z^+$, then either $a$ or $b$ is even.
Lemma If $a^2$ is even, then $a^2 \equiv 0 \mod 4$. Proof. If $a$ is odd, then $a^2$ is odd, so since $a^2$ is even, $a$ is also even. Thus $\exists k$ such that $a=2k$ and so $a^2 = 4k^2$, as desired.
Feb
19
revised How to prove a set is open
added 32 characters in body
Feb
19
answered Convergence of a stochastic process to another?
Feb
19
revised Volume of revolution over x-axis
added 18 characters in body
Feb
19
reviewed Approve suggested edit on If $m < n$ and $p < 0$, then $np < mp.$
Feb
19
revised Need help with a math proof
edited body
Feb
19
awarded  Enlightened
Feb
18
comment random graph on the reals
I am wondering what the notion of a graph isomorphism applies to random graphs -- you only know the number of vertices, not the edges?
Feb
18
awarded  Nice Answer
Feb
18
comment Solve linear equation system $A'Ax=A'Bz$
@Manuel what do you mean by alternative technique - alternative to least squares or an alternative to QR decomposition implementation of least squares?
Feb
18
revised Sample space of possible outcomes for a knockout tournament
edit for easier reading
Feb
18
revised Solve linear equation system $A'Ax=A'Bz$
added 268 characters in body
Feb
18
answered Solve linear equation system $A'Ax=A'Bz$
Feb
18
answered Calculating how many iterations to make a list that doubles each iteration, n elements long
Feb
18
revised Need a function that matches criteria
added 430 characters in body
Feb
18
answered Need a function that matches criteria
Feb
18
comment calculate the sum of n initial terms of the sequence
No one said life was supposed to always be easy :-). On the other hand, this is a very useful and often needed result. It helps to derive it once and keep in your toolbox forever.