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location Caltech
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visits member for 1 year, 7 months
seen Dec 10 at 0:49

Caltech Undergraduate Math Major


Oct
19
answered Finding supremum and infimum of a given set and proving it formally
Oct
18
comment Finding supremum and infimum of a given set and proving it formally
Are you defining $0 \in \mathbb N$ or not?
Sep
30
awarded  Explainer
Sep
28
answered Concerning Cyclic Groups
Sep
24
awarded  Autobiographer
Sep
11
comment Maximum value of $a+b$ given that $\frac{1}{a} + \frac{1}{b} = \frac{1}{20}$
Some people include 0 to $/mathbb N$ while others do not. Imo $/mathbb Z+$ is more clear.
Aug
28
comment Proof of $x*0=0$ is invalid?
@AWertheim You're likely correct. My number theory is bit rusty. My point was more explaining why the original proof wasn't sufficient, and that this would suffice, assuming of course that I hadn't assumed anything I wasn't supposed to appeal to. The accepted proof (based on a brief skim) is more elegant, and accepted in general for the reason you gave.
Aug
27
comment Proof of $x*0=0$ is invalid?
iirc a lot of these "obvious," statements come form distributive laws. This becomes a lot more messy in Boolean algebras where you want to prove associativity, but fortunately, you're not dealing with that.
Aug
27
answered Proof of $x*0=0$ is invalid?
Aug
27
comment Proof of $x*0=0$ is invalid?
To clarify Mike's point, you showed that if there is an a such that a*b=a, then a is 0. However, you failed to show that such an a must exist.
Aug
7
comment Proof of trigonometric identity $\cot \theta \sec\theta= 1/ \sin\theta$
You might wish to note that (most simple) statements are true or false. In this case it is either provable or an axiom. You might wish to think about the problem as "how should I prove," rather than "is it possible to prove."
Aug
3
comment Spherical bread slices area
TBH I'm not sure how to solve it with the approach hinted at in the comments. I thought the question seemed interesting, and I agree that the calc approach is likely better. But the OP asked for the classical solution,I'm not entirely sure of the relevance, though it is clear, and does explain why the statement is true.
Aug
3
comment Number of solutions of $1000 / x = y$ where $x$ is a positive integer and $y$ is a $2$-digit positive integer
This question (at least now) uses 1000 rather than 100
Aug
2
comment Spherical bread slices area
I feel like this answer is more of a clarification, i.e. how to do the problem using calculus, as it doesn't really add any suggestions for the solution other than those in the comments. Am I missing something?
Jul
30
comment Proving the following inequality in a triangle
Are D,E,F arbitrary? Or are they midpoints? If they are midpoints, then you can use the properties of centroid to say 1/3+1/3+1/3=1
Jul
30
comment Proving the following inequality in a triangle
Can we have a diagram? Or an explanation as to what these are. Is this a Triangle ABC with midpoints D,E,F?
Jul
30
revised Finding an ODE with specified solutions
cleaned up some latex
Jul
30
suggested approved edit on Finding an ODE with specified solutions
Jul
29
revised Practicing the arithmetic-geometric means inequality
added LaTeX
Jul
29
suggested approved edit on Practicing the arithmetic-geometric means inequality