1,220 reputation
317
bio website andrew-christianson.github.io
location Los Angeles, CA
age 23
visits member for 3 years
seen 4 hours ago

Jun
1
comment System of two Equations
@thomas some of your confusion on Robert's answer below may be stemming from the graph you used. I'm not sure what you used to graph the equations, but it has plotted both branches of the square roots. If you were to plot the initial system of equations implicitly, a la: i.imgur.com/ayQ6m.jpg you can see there's only one real solution
Jun
1
comment How to integrate out a function parameter
Perhaps I'm a bit dense, but I'm not seeing what you intend $p(x|a,b)$ to mean. I would interpret that as a the probability of $x$ conditioned on $a,b$, but given the rest of your question, I don't think that's what you meant. Could you be more specific/expand your notation a bit?
May
26
comment Must probability density be continuous?
If I recall correctly, there is a restriction to at most countable discontinuities.
May
18
comment Get p from cumulative binomial function
@copper.hat pretty clear from the derivative: $\frac{d}{dp}((1-p)^{10}+10 p (1-p)^9) = -90 (p-1)^8 p$
May
11
comment What was Cayley's formula for the number of invariants? (Lost Formula!?)
Furthermore this entry would seem to imply that the majority of Cayley's work on the topic was published in the ten 'Memoirs on Quantics' (which they mistakenly spell as quanties). Fortunately, all ten are available on JSTOR here. Based on the encyclopedia, the First or Second memoir seems the most likely source for the expression.
May
11
comment What was Cayley's formula for the number of invariants? (Lost Formula!?)
Also TA Springer's 'Invariant Theory' from this paper: sciencedirect.com/science/article/pii/S0195669806000916
Apr
10
comment What is the fastest/most efficient algorithm for estimating Euler's Constant $\gamma$?
@Ronald interesting than the trivial methods. Moreover, the mathematics that are used to create those non-trivial methods can find application elsewhere. Finally, the values they generate can be used to test and benchmark supercomputers. In short, the computation of constants is not nearly as pointless, simple or droll as you imply.
Apr
10
comment What is the fastest/most efficient algorithm for estimating Euler's Constant $\gamma$?
@ronald the other commenters are referring to the computational cost of various operations. The costs are minute to be sure, but require significant computing power when performed billions (or trillions) of times to compute constants to high degrees of precision. As for why one would ever want to carry out those calculations...why do we compute Pi beyond the 14-15 decimal places necessary to given the circumference of the universe to within the diameter of a hydrogen atom? Because it's a mathematical challenge; the methods for computing constants quickly are vastly more complex (and thus)
Apr
1
revised Math Database For Problem Descriptions In An App.
spelling corrections.
Apr
1
suggested suggested edit on Math Database For Problem Descriptions In An App.
Feb
14
awarded  Nice Answer
Feb
7
comment Good books for 4th graders focusing on fun, interesting and challenging math topics and exercises
What sort of math is he doing right now? What's really capturing his interests?
Feb
5
answered Trigonometry & circle math
Feb
5
revised Trigonometry & circle math
edited tags
Feb
5
revised Trigonometry & circle math
TeX for readibility
Feb
5
suggested suggested edit on Trigonometry & circle math
Feb
5
answered What does integration do?
Jan
29
comment How can I find the square root using pen and paper?
@david effectively $x_{n+1}$ is the formula for calculating the next term given the $x_{nth} term.
Dec
16
comment What is the convention for using results of theorems left as exercise in the text?
I already have, waiting on a reply. I was just curious to see if there was some established rule here.
Dec
16
asked What is the convention for using results of theorems left as exercise in the text?