Recent content by BananaMan

how do you sketch the area of x or y to infinity though?

no, we have gone over polar co-ordinates, but never with an integration limit of infinity so i have no idea how to convert the limit to evaluate it

i have the integral \int_{0}^{\infty} \int_{0}^{\infty} (-x^2-y^2) \ dx dy (double integral with both limits the same...assuming my first bash at the tex comes out it says to transfer it into polar form and evaluate it i have no idea how to convert a limit of infinity to polar form, help...

the equation is correct once it is in terms of R and \theta there is nothing more you can do with it

heres the question: anti-reflection coatings on a glass lens (n=1.50) consists of a magnesium fluoride (n=1.38) film, the coating thickness is chosen to eliminate any back reflectionusing the ideas of destructive interference. What is the minimum coating thickness required to eliminate the...

i was working under the assumption you was allowed to use the accepted value of acceleration due to gravity, if you arn't you would have to use this, but if not the problem is fairly simple, just look up the value in your book of constants (if you can't remember it)

ooops sorry, its late and I am tired, should probably get myself off to bed, just one more crack at my optics and i will i think

remember that f=1/T when doing this calculation

well, let's look at this, you have a mass and you know the acceleration due to gravity, what equation links an acceleration a mass and a force? (this is actually the only formula you need) you then should be able to work out the normal force knowing the box isn't passing through the surface...

exactly, now go have lots of fun integrating (god wish i wasn't this ill so i could go drinking, saturday nights in are boring lol)

it isn't a product so no the product rule should not be used, its just 1 basic rule "the integral of sin(ax) = -1/a cos(ax)" ive explained why (although not too well) in my post above

from my notes (as I am studying this aswell) i believe your answer from (b) should lie... or could possibly be I= N^2 * Io for a i would use asin\theta=m\lambda as well but I am not so sure on this one, optics isn't exactly my best subject at the moment

thanks, glad i managed to work it out, hope something like that comes up in my exams

the best way to think about integration in general is the opposite of differentiation if you can visualise what would differentiate to what you are trying to integrate you have cracked it for this specific question though, cos differentiates to - sin... so sin integrates to - cos when...

not that i can answer this but if you read the FAQ you are supposed to show some working or some effort to have started your problem, maybe if you do that you will have more of a chance of it being answered