Lizwi

If you study degree online, like honours degree, how do you get certificate after completing?

Yes, I understand the variables. Thanks, your explanation is very clear. I think I can classify PDEs now according to their linearity.

For example Is the first equation linear or non linear?

They said " Linear equation is the one in which there is no products of the dependent variable and its derivative.

Hlw. Still I failing to understand the difference between Linear, semilinear and Quasilinear pde even after reading from Google. Can anyone clarify for me please.

Okay, thanks, the Sun is too small. Is there a general Shwarzchild radius for objects to become a black whole?

Yes, as long as that point rotates interactively with the axis of a disk or that circle

1. Is there an evidence for black holes 2. Is singularity possible? 3.If the Sun becomes a blackhole, will the planet's continue to revolve as if the Sun is still present?

Why can't the Sun form a black? , because it can collapse too.

Ahhhr!, THANKS A LOT. I GET IT.

Why is s ranging from r - R to r + R, can anyone show me me which distance is r -R and which one is r+R

Does the electron change the direction as it passes through a slit?

Thanks, does that mean the pressure at the bottom of any fluid is atmospheric pressure?

Why atmospheric pressure measure at the bottom of this fluid because atm is exerted by atmosphere and the atmosphere is at the top of the fluid? I though atmospheric pressure should be measured at P0