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1d
comment How does this textbook determine when this function diverges?
i think you mean it's obviously not valid where $(1+2x)^3 = 0$
1d
comment Why is it possible to find the birth year by subtracting one's age from 114?
Today I'm 25, so i was born in 1989, but if tomorrow's my birthday then i was born in 1988?
1d
awarded  Constituent
2d
comment Should I Put My Lifesavings into the Lottery?
If you are risk averse, I'm sure you wouldn't. Maybe you should rephrase your question (I think you really mean to ask about the expected value here).
Dec
11
comment Why do we focus so much in math on functions (as a subclass of relations)?
Maybe related: mathoverflow.net/questions/121031/…, math.stackexchange.com/questions/354779/…
Dec
11
comment Best metric to measure histogram quality
i'm speaking out of turn here, but why don't you calculate a squared error (or something) on the difference between a reference histogram (like the 1st) and the lower quality ones?
Dec
11
comment Best metric to measure histogram quality
if you don't get an answer here, maybe the signal processing or statistics stackexchange could help.
Dec
11
comment Don't see the point of the Fundamental Theorem of Calculus.
The definition of (one kind of) an integral is the limit of a riemann sum, how do I know a priori that the given limit is an antiderivative?
Dec
9
comment Soft question: A good book for introduction to Lie group book
what's your background? what book is required by your course?
Dec
8
awarded  Caucus
Dec
5
awarded  Popular Question
Nov
22
comment basic calculus/analysis question. why is $\frac {dy}{dx} dx = dy$?
Well, think about what $\int y'(x) \mathrm{d}x$ is equal to. It's really just formal a formal expression at the intro calc level though.
Nov
2
comment If $H$ is a subgroup of $G$ and $a, b \in G$, how is $aH=bH$?
if $Z_4$ and $Z_3$ are the cyclic group on 4 and 3 elements, $Z_3$ is not a subgroup of $Z_4$... $Z_4$ has no element of order 3.
Oct
21
comment Finding drop payment with varying interest rates..
payment will be between 0 < Payment < 100. That is the drop payment.
Oct
21
comment Finding drop payment with varying interest rates..
Problem strategy: Find the accumulated value of the payments (i.e. the balance) on May 1, 2005 (until this point, it is an annuity at 12%). From there, that balance accrues interest at 10.5% until the fund hits 10,000. At the same time that is accruing interest, you have the $100/mo annuity accruing interest at 10.5%. What you want to find is when this hits 10,000 dollars. It will undoubtedly be between two end-of-month payments. The drop payment is a final, lower payment, bringing you to 10,000. I.e., at some point you will have an account balance of 9900 < Balance < 10000, and the final...
Oct
21
comment Finding drop payment with varying interest rates..
well, do you know what a drop payment is?
Oct
18
reviewed Approve Expected value for number
Oct
12
awarded  Yearling
Oct
11
comment Why get the sum of squares instead of the sum of absolute values?
Also: minimizing sum of squares penalizes large deviations much more than sum of absolute values.
Oct
10
comment 182-Day T-Bill vs. 91-Day T-Bill
Bankers are extremely clever, and, not unlike 99.9% of homework problems, this question shows a stupidly oversimplified situation which would never occur in practice.