Recent content by Lemniscates

Ah. That's interesting. But what about problems involving physical pendulum calculations? From what I've read and have been taught, when you calculate the torque induced by gravity in a physical pendulum, you use the distance from the center of mass to the pivot as the length of the moment arm...

Hey all, Perhaps this is a bit stupid... I'm familiar with the normal procedure of calculating rotational inertia (using integration, parallel axis theorem, etc.). However, I had a confusing thought: if the center of mass of a body is the point at which you can treat as all of the mass being...

A lot of that notation is new to me, but I've done a little bit of Googling to make some sense out of it. I'm still confused. What is the probability density function in this case? It wouldn't be c*e^(-r^2) would it? Because to me that seems like a function that takes a real number and puts out...

By the way, should I be asking this in homework help? I felt my question was mostly related to the concept of integration and not the specific question, so I posted it here.

I was reading this problem on calculating the probability of hitting a certain region on a dartboard. The number of hits the dart thrower will land at a certain radius R on the dartboard is proportional to e^(-R^2). The task is to take a certain portion of a ring (or annulus) on the dartboard...

Thank you, HS, for helping me find the hole in my proof. And thank you mathman, but I've already seen the actual proof, which makes sense to me. I just needed someone to explain why my version didn't work.

Hello all, I'm having trouble with proving that the derivative of f(x)*g(x) is f'(x)*g(x)+f(x)*g'(x). Now, I've already seen the actual proof, and I can understand its reasoning, but the first time I tried to prove without looking at the solution, this is what I wrote before I became rather...

Ah, I think I see now. So f'(-x) would be df/d(-x) (change of f over change of negative x as a single quantity), while (f(-x))' would be df/dx?

I was doing a proof on why the derivative of an even function is odd and vice versa. Now, the way I did the problem was by using the chain rule to rewrite the derivative of f(-x), and the proof worked out perfectly fine. But I had a thought that I can't quite wrap my around, and I think it's...