# Recent content by Dafydd

This is a pretty general question that I haven't found an answer to, so I'd really appreciate the help. Let's say we have 3 tasks - Alpha, Bravo and Charlie, all within the one and same procedure. Alpha takes calls from Bravo, which in turn takes calls from Charlie. Alpha's entry is...
2. ### Context Sensitive Grammar (Automata theory)

That's all I needed to hear. Thank you!
3. ### Context Sensitive Grammar (Automata theory)

Sorry if this is the wrong forum. I'm trying to get my head around Context Sensitive Grammar. In my coursebook, there's an example ('e' here is the empty string, epsilon, and 'E' is the "set member" symbol): The language {an bn cn | n E N} is described by the following rules: S -> e | abNSc...
4. ### Relating probability distributions huh?

Homework Statement Problem description: A variable X has expected value 0.002 in meters. Consider X - 0.002, scale to millimeter, and we get Y. Tasks: a) Express Y as a function of X b) Relate the probability distributions FX and FY c) Relate the probability density functions fX and fY...

6. ### Probability. Why can't I add them?

Homework Statement Let's say, at a certain university, over the last few years 100 students have graduated with a degree in Computer Science, and another 100 in Biology. Let's also say 60 of the CS graduates found a job within 3 months of their graduation, and 50 of the Bio graduates did. The...
7. ### Getting n alone in n!=x and nlgn=x

Homework Statement I need to know the greatest n for which n! is greater or equal to x, and the greatest n for which nlgn is greater or equal to x. Homework Equations Can't think of any. Sorry! The Attempt at a Solution For a "normal" function, like, say, lgn or n^2, it would be...
8. ### McLaurin - when do you stop?

Homework Statement I have a problem with McLaurin series. I never know when to stop. How do I know if O(x3) is adequate, or O(x5)? Let's take this exam question as an example. \lim_{x \to 0} \frac{(x+1)e^x -1-2x}{cosx-1} \frac{(x+1)e^x -1-2x}{cosx-1} = \frac{(x+1)(1+x+\frac{x^2}{2!}+...)...
9. ### D/dx |x+2|^x (solution known, need explanation)

Cyosis - got it, thanks! g_edgar - I agree, but the example was taken from an old exam and what I wrote in the first post was the only answer or explanation given in the solutions. I don't know if a solution taking two cases would have given full credit.
10. ### D/dx |x+2|^x (solution known, need explanation)

Ok, yes, you're right. Thanks! Not that it matters that much to me right now, but how is it a consequence of the chain rule?
11. ### D/dx |x+2|^x (solution known, need explanation)

Hm. \frac{d}{dx} e^x = e^x \frac{d}{dx} x and \frac{d}{dx} ln|x| = \frac{1}{x} so \frac{d}{dx} e^{x \log|x+2|} = e^{x \log|x+2|} \frac{d}{dx}(x \log|x+2|) = e^{x \log|x+2|} (ln|x+2| + \frac{x}{x+2}) = |x+2|^x (ln|x+2| + \frac{x}{x+2}) Thanks for the tip, I would never have thought of...
12. ### D/dx |x+2|^x (solution known, need explanation)

Solved! d/dx |x+2|^x Homework Statement I need someone to explain this: http://www.dafydd.se/stuff/solvethis.png [Broken] Homework Equations I guess the following are of relevance... \frac{d}{dx} |x| = \frac{x}{|x|} \frac{d}{dx} a^x = a^x ln a The Attempt at a Solution The...