Recent content by Doc G

Great! Thank you very much for the advice

Thanks, I think I've got it now; but just to check here my full working: let I = \int_{0}^{\frac{\pi}{2}} e^{t}\sin t dt u = sin t dv/dt= e^t therefore du/dt = cos t v = e^t so: I = e^{t} sin t - \int_{0}^{\frac{\pi}{2}} e^{t} cos t dt and integrating by parts again: u = cos t dv/dt...

Taking the result of the first integration by parts: I = - e^{u} \cos u +\int_{0}^{\frac{\pi}{2}} u e^{u}\cos u du then working with the integral part: +\int_{0}^{\frac{\pi}{2}} u e^{u}\cos u du let u= cos u therefore \frac{du}{dx}= - sinu let \frac{dv}{dx}= u...

Hi, Homework Statement find value of \int_{1}^{e^\frac{\pi}{2}} \sin (lnx) dx Homework Equations The Attempt at a Solution I first used subsitution u = lnx, that gave me: \int_{0}^{\frac{\pi}{2}} e^{u}\sin u du then letting I = \int_{0}^{\frac{\pi}{2}} e^{u}\sin u...

Thanks, should I now attempt to find a close solution by iteration [we've only just covered the basics of which in class]? And would the correct formula for which be: x_{n+1} = x_{n} - \frac{\ln3x_{n} + x^2_{n}}{1/x_{n} + 2x} ?i tried putting in the equation ln3q + q^2 = 0 into Newton's...

Thanks for the replies. Okay we haven't really covered much differentiation of ln graphs yet, but using what hootenanny/HallsofIvy posted, should the equation therefore be ln(3q)/q = -3q giving: ln(3q) + 3(q^2) = 0 is this right? and how could i solve that? thanks again

Since when the normal and the curve y=ln(3x) intersect, the x coordinate is q, the the y coordinate is thus ln3q. And since the normal passes through (0,0), the gradient of the normal can also be expressed as (ln3q)/q I believe also that the gradient of the normal can be expressed as -q...

I was wondering if anyone could help me with a question I was trying to work through today in our A-level math class. Homework Statement a. Sketch the graph of y= ln(3x) b. The normal to the curve at Point Q, with x coordinate q, passes through the origin. Find the equation of the...

Many thanks for the reply. I myself have been able to run BF2 on the AGP version of NVidia's FX5200 256mb graphics card. NVidia also produce a PCI version of this card but will the performance be the same or is it affected by the slower interface [PCI vs AGP]? Thanks again..

Hey everyone- a friend of mine is looking to buy a new PCI [not PCI express] graphics card- he justs wants something that will be able to run most new games - though not at any great quality. Does anyone know if a graphics card ~70 euro would be able to run games such as Oblivion and...

Thank you both very much for your replies. I'll try to get my head aroud it as I'm probably still a couple of years off learning this in physics. Though if I combine your two replies I'm sure my geography teacher will be impressed :smile:

Ok, this may sound a little basic but I can’t think of a way of explaining it other than common sense. I should also say that this is for a Geography assignment so not really physics but hope you guys can give me an insight. I’m trying to explain why the steeper the gradient of a river, the...

Is it running msconfig.exe what you are thinking of? You can disable processes that start up with your system there. I've only ever fiddled with the stuff on the 'startup' tab. However my quicktime seems to have a habit of coming back even when disabled.

I'm not sure in this forum that we can just give you the equation but you should be able to work it out form the information given. This table should make it clearer. Number of half-lives Mass of Carbon-14 (g) 0 32 (32/1)...

Lets start with what a half-life is- how long it takes until a substance has lost half its mass. Therefore, in one half life (in this case 6000 years), half of the mass of the substance will be ‘lost.’ Thus, after 6000 years, only 16g (32/2) will remain. In another 6000 years (after 2...