Recent content by Nick Jarvis

Thanks. I copied and pasted from Word and assume the bold was inherited from the the 3 titles in the template. Apologies for that. I cannot work out to insert nice equations like the two that you have inserted above. And yes, I need to prove that: E(Xr)=Γ((r/B)+1) - your first equation When I...

Homework Statement I have f(x) = BxB-1e-x^B I need to show that E(Xr) = Ƭ(Gamma)(R/B + 1) Homework Equations I know that E(Xr) = f(x) The Attempt at a Solution Attempt at part of solution I started by saying let u = xB so du = BxB-1dx Can I say then that if u = xB, then Xr = ur/B...

Apologies. Have spoken also to my tutor and I have now worked it out. Thanks for your input. Much appreciated :)

However, if I have ∫BxB-1 e-xB dx, can I not integrate by substitution? Let u = xB so du = BxB-1dx which gives: ∫e-udu and therefore the answer is -e-xB + c I know that is not correct, but I thought I could integrate by either substitution OR parts? This integration is key to me understanding...

ok. I have integrated ∫xn ex using parts and I get: xn ex - ∫exnxn-1 this equates (I hope) to: ex(xn - nxn-1) this can be simplified obvs. Is this correct? Thanks

Thanks BvU, will take a look this evening.

Hi. I think I jumped too eagerly into my latest module, as I am positive it makes many assumptions on previous experience. I am obviously lacking. I have created a question in Word, but the equations don;t appear to be copying into this thread. So I have uploaded question instead. If this is...

Apologies for the lateness. Many thanks for your replies. May need to speak to tutor as we have not covered area at all! Cheers

Hi The question is about diseased trees in an area (Poisson process), and states that λ = 15 diseased trees in a km square. I need to calculate expected distance from a point in the square to a diseased tree. Now I thought that this means that P(diseased tree = 0) ~ Po(15) = 3.059 x 10^-7 Or...

Thank-you both. For some reason I was making it way more complicated than it needed to be. Going to work through a few more examples now. Again, a huge thanks :)

Thanks v much. I cannot find this in my notes at all. Assuming the -108V is due to 3sf? Rather than my 108.5V? So 150V at the origin. I then resolve in the x and y direction. Cannot work out though why it is 150V - 150V -108V, when we're looking at the +x/y directions? Like I said, this should...

Thanks BvU. Have I done anything correctly? You're spot on with the result, I just cannot work out how to get there. Cheers

Homework Statement In a certain region of space, there is a uniform electric field of magnitude 25.0 V m^-1 directed at 30.0 degrees to the direction of the positive x-axis and at 60.0 degrees to the direction of the positive y-axis. (There is no z component of the electric field.) The electric...

Thanks Dr.

I have a complete brain freeze sorry, and cannot work this out. I have a helium atom of 4.0 amu and there are 6.0 x 10^24 atoms. How do I calculate the total mass in kg please? Thanks