662 reputation
412
bio website ecosimulation.com/chrisgregg
location Somerville, MA
age 42
visits member for 3 years, 3 months
seen Jun 6 at 19:09

PhD, computer engineering. iOS developer. Recently mobilized with the Navy as the Information Operations Department Head, Combined Joint Task Force Horn of Africa, Djibouti, Africa.


Jul
31
awarded  Yearling
Apr
25
awarded  Popular Question
Aug
30
awarded  Good Answer
Aug
30
comment Is there another simpler method to solve this elementary school math problem?
@MarkLakata I think it could be used as one of those examples to show young students that a good tool to have in your problem-solving toolbox is to try to sketch out a solution. I would start out by saying, "hey, what if everyone had bicycles?" Then, "what if this kid had a tricycle? How many wheels are there now?"
Aug
29
awarded  Mortarboard
Aug
29
awarded  Yearling
Aug
29
awarded  Nice Answer
Aug
29
awarded  Editor
Aug
29
revised Is there another simpler method to solve this elementary school math problem?
deleted 25 characters in body
Aug
29
answered Is there another simpler method to solve this elementary school math problem?
Aug
26
comment If $0<c<1$, then show $0<c^2<c<1$.
This reminds me of a story my cousin told me about his college fraternity: they had a list of all the people currently in the "square root club." To get into the club, the square root of your GPA had to be less than your GPA. :/
Aug
15
awarded  Commentator
Aug
15
comment Should I put number combinations like 1111111 onto my lottery ticket?
@Dan I think you're on the right track (i.e., avoiding birthday numbers), but a better strategy would be to randomize your pick of only numbers greater than 31. Then again, you may find that there are many people with the same idea as you, which brings us back to the original problem.
Jul
19
comment Solving a simple exponential equation
@jaykirby You have to "see it" as you might see a quadratic equation: First, determine that $e^{2x}=e^x\times e^x$. You will thus have $(e^x\pm \_\_\_)(e^x\pm\_\_\_)$. Then, look at the coefficient of the last term, and find its factors (in this case, 2 and 1, or -2 and -1). Then see if those factors add to the coefficient of the middle term (-2 and -1 add to -3).
Jun
20
awarded  Critic
May
31
comment How can I find the surface area of a normal chicken egg?
@jk I'd argue that this question doesn't really fit into math.SE to begin with -- if you're looking to measure a real object, you've entered the realm of (as you say) experimental physics, or engineering. Both use mathematics, but mathematics itself won't determine the answer.
Mar
6
awarded  Nice Answer
Dec
18
comment In the induction proof for $(1+p)^n \geq 1 + np$, a term is dropped and I don't understand why.
Thanks! This was my original confusion. Once I understood that we already know that $(1+p)^n \geq 1 + rp + p + rp^2$ so we can drop the last term without harm, it started making sense. I was originally thinking that we were trying to show that the left side was greater than the right side, which is why I didn't understand how we could drop the last term.
Dec
18
awarded  Student
Dec
18
awarded  Yearling