now that's the very same machine that my computer genius friend got, and which I got to admire for an entire week last week as we were working on some project together, he certainly warmly recommended it to me (however it's more than I was planning to spend), now this machine should run anything, but I understand that not all the cores will run unless you somehow write your programs specifically to run in parallel (or something)... anyhow hours of fun I should think.

let us know how fast your maple worksheets run on it!

oops, sorry

oops, sorry

no problem here with 13/Classic/Windows.

no problem here with 13/Classic/Windows.

thanks acer, that's good to know,

Patrick.

thanks acer, that's good to know,

Patrick.

Robert, is there an "optimal" height-width ratio? I always pick 400-400, but I don't know any better. Is there a reason why you have "height=500, width=640"? is it more pleasing to the eye or is it a standard format? thanks.

Robert, is there an "optimal" height-width ratio? I always pick 400-400, but I don't know any better. Is there a reason why you have "height=500, width=640"? is it more pleasing to the eye or is it a standard format? thanks.

that's the problem with small-sample inference, I've only ever experienced one Tosbiba laptop! Japanese electronics do have a good reputation. I've had three Dells, neither of which passed the 18 months mark without major problems (all three keyboards failed, plus other things too), everytime I went back because the specs/price ratio seemed the most attractive, and because I believed (incorrectly it turned out) that I'd been unlucky and that the next Dell would last. I'm definitely moving on now (clearly the price is less of an issue than when I was a student). I've had two HPs, they were great. I nearly got another one recently, but the touch pad had been placed in the far-left where I like to rest the palm of my left hand, so I didn't. I've had two IBMs, the ugliest thing ever called a "laptop", but I must say absolutely nothing failed on those, not even in the HK humidity. Why don't I buy more of them IBMs? Gee I don't know. Oh yes, I do. they are SO ugly. I can't complain about Sony except that they are expensive, I should have bought more of them but the price put me off -- the latest Sony models are very slim, I may get one of them next time. My mom's apple thingy is gorgeous, there's a thought. The Dell technician recommended Fujitsu -- I've never tried them.

Heat. That's the first thought that comes to my mind when I hear Toshiba. Now I'm no expert, I've only ever owned one Toshiba laptop, and I may well have been very unlucky, but that was the most over-heating machine ever (otherwise superfast, supernice). Consider this: I could not actually keep it on my lap, isn't that ironic for a lap-top?! I ended up purhasing at least five different ventilator tables, none of them any good, and I was only too glad when the machine expired on me one week after the one-year warranty had expired.

I put it in the trashcan outside my flat, the caretaker rang the bell to ask if I actually meant to throw it out this way (or perhaps I mistook it for a burnt piece of toast) -- yes absolutely, in the trashcan, with cable and all!

Hi Rob,

I can't recommend any cpu in particular, but here's my HK experience ;-)

The weather has burned my laptops pretty much within the year, at best I've managed to make them last 18 months. The big culprit has been humidity. I too carry my laptop everywhere and use it every day at least ten hours. My strategy is to spend a maximum of 2,000 US dollars (15,000 HKD) and get the most powerful machine at that price -- or less if there's an economic depression. My expectation is that I'll need to spend that every year. If I manage to stretch a laptop to the two-year mark, it feels like I just made 2,000 dollars.

My latest purchase is worth describing in full. I bought a laptop named after someone called Michael, if you get my drift. The specs were very attractive.  I can't complain about the performance, but: within the first month I had to do a clean windows install -- first, the amount of bloatware was unacceptable, secondly, the company had used all the available partitions for their to-me-useless dvd-music quick-boot-system, so I had to install everything again and create my own partition to have my linux on the internal hard drive. Huge waste of time. (You would think that you should be able to request a double partition if you wanted one, but in HK they won't bother to offer this service, so you must take what they have.) Within the second month, the battery failed. Within the third month, the power cable failed. One month later, the hard drive failed! (imagine the waste of time, plus I lost one day's work) And just one month before the end of the one-year warranty, the screen failed. True, every time the company sent someone to replace the parts on-site (I may have paid extra to get this service), but this laptop experience was hell, so I'm not buying this brand name ever again.

One reason for this, I think, is that the company puts together hardware that taken separately is attractive, but is not made to be bundled together. You get a lot of overheating and inefficient coordination across parts. So I think it's important, for performance, to make sure you get a "stable" model, something that's been tested and improved, as opposed to a laptop with ever-changing architecture.

There are two minor things that annoy me greatly with laptops nowadays, first they overheat crazily, secondly the touchpad is not in the middle. That makes it less and less attractive to buy online, so now I tend to buy from shops, at a higher price.

you may need to make assumptions about the sign of your parameters in your expression before Maple can compute a limit. you can use either the "assume" command or "assuming" syntax.

Have you tried plotting your expression for given values of the parameters? That would give you some hints about the likely value of the limit (if any), just plot the expression in terms of sigma and see what happens when sigma is close to 0, then change the parameter values and look at it again, I would do that as a first step.

The following should contain enough clues to show that your solution set is empty:

plot([sin(t),cos(t),exp(t)], t=-10*Pi..Pi);

solve(sin(t)=cos(t));
                                  Pi
                                 ----
                                  4

plot([sin(t),cos(t),exp(t)], t=0..Pi/2);

The following should contain enough clues to show that your solution set is empty:

plot([sin(t),cos(t),exp(t)], t=-10*Pi..Pi);

solve(sin(t)=cos(t));
                                  Pi
                                 ----
                                  4

plot([sin(t),cos(t),exp(t)], t=0..Pi/2);