Recent content by HeilPhysicsPhysics

y=(1+1/x)^x Let u=1+1/x,y=u^x y=u^x ln y=x ln u y'/y=x/u dy/du=[x/(1+1/x)](1+1/x)^x =x(1+1/x)^(x-1) du/dx=-1/x^2 dy/dx=(dy/du)(du/dx) =x(1+1/x)^(x-1) (-1/x^2) =-(1+1/x)^(x-1) /x

I don't understand what is the meaning of "flux" .I just know it has some relation between eletromagnetism.Please explain what is flux to me.

Why there is a probability to go through a wall?

What meaning is divergence and curl in physics?

But why we call it "wave"? And is its amplitude mean probability?

Why we have to definte covariant derivative?

Just like: A=i+j+k B=2i+3j-4k They are both vector. I heard that a vector times a vector become a tensor(rank two). If ij=-k,ik=-j,jk=-i. The product is: (i+j+k)(2i+3j-4k)=-2-3k+4j-2k-3+4i-2j-3i+4=i+2j-5k-1 I think it is still a vector, not a tensor(rank two).

How to prove e^ix=cos x + i sin x

For example Intergrate (uv dx)=? Intergrate (u dx/v)=? Intergrate (u^v dx)=? Intergrate (log_u v)=? Where u and v are the function of x. Is there any method in intergration just like dy/dx=(dy/du)(du/dx) in diffrentiation?

What is a blackbody?What special of its radiation? What relation between blackbody radiation and quantum theory?

Why do we think particle is wave and probability also wave? If probability is wave,what is its wavelength,frequency,amplitude,period?

What does a divergence calculate? What meaning is it for a vector? And also what is curl? Why we have to definte divergence and curl?

For example: i^2=? j^2=? k^2=? ij=? jk=? ik=? ijk=? Is ij=ji? And how to prove them? And also,vector times vector, what is the product?

What is the metric tensor on a spherical surface?

Tensor is a general vector.