Recent content by dpa

Generally, when we talk about moment of inertia, we talk about rotation and inherently, we talk about moment of inertia about an axis. But when we talk about inertia tensor, we calculate about a point. Is there a reason for this difference? Am I missing something? I am new to tensors.

Flux through sphere Homework Statement Given \vec{F}=\frac{\vec{r}}{r^2} and unit sphere, find the flux through the surface of the cube. Homework Equations Surface Integral of F dS=volume integral of Div. F d^3r The Attempt at a Solution After the above formula, I do not have...

So, what exactly is it when people refer to "density" or similar notions when they discuss about Riemann Stieltjes integral. Is it how how fast alpha(x_i) grows? in the interval?

Hi all, Homework Statement Is the difference between riemann stieltjes integral and riemann integral that in riemann integral, the intervals are of equal length and in riemann stieltjes, the partitions are defined by the integrator function? If not so what exactly is it that integrator...

Suppose I rearrange the equations, then P=700-0.125QD [which is fine without reflection and same as QD=5600-QD] But, next P=0.25QS-125 but the graph is for 0.25QS+125. Note the + and _ after QS. It works with reflection. but not normally. Is there a certain convention. I mean am I always...

Hi everyone, I am having hardtime understanding this problem. I have two functions: QD = 5600 – 8P QS = 500 + 4P Why is the graph like the one attached and not the normal mathematical graph where supply curve starts from y=(0,-125)? Do ignore the consumer surplus and producer surplus part. That...

Thank you. That was somehow helpful. It is defined over the set of rational numbers for the relation you specified. Yes, I do not understand much and I find my notes/textbook insufficient. I searched online for some explanations, examples and did not find much information there. Still, thank You.

Homework Statement A solution to a problem has following operation: here, [(a,b)] and [(m,n)] are two equivalence classes. [(a,b)]+[(m,n)]=[(an+bm,bn)] Is not [(a,b)]+[(m,n)]=[(a+m,b+n)]? Can anyone explain it to me? Homework Equations The Attempt at a Solution

Hi Dick, Thank you for your suggestion. I am sorry for not including some point. I am actually looking for algebraic proof. Thank You.

My goal actually is simpler. I have to prove (\stackrel{2n}{k})=\Sigma^{k}_{l=0}(\stackrel{n}{l})(\stackrel{n}{k-l}) I can't properly use latex but hope you can understand it. I wanted to follow the above pattern to prove it, but if there is a simpler method, that would be helpful...

Thank You. That was very very helpful.

:smile: Thank You.

Homework Statement I need to derive the prarametric equation of a certain torus. defined by a unit circle on xz plane with center (a,0) and revolving about z-axis. Homework Equations * I don't know if this is relevant but here is something from wikipedia. Surfaces of revolution give another...

Hi All, Homework Statement This is algebraic proof of Vandermonde's identity: I am having some problem understanding how we reached the second last step and more importantly, last steps from revious steps. src::proofwiki.org I would be grateful if someone would elaborate it clearly...

Thank you.