in the diagrams below, what does it mean when the dot for example Vb is filled in with black and Vin is not?

 

Hello,

Is there no explanation for the used conventions in the book?
I think that the open dots are variable inputs.
The Vb at the closed dots are fixed bias values.

Bertus

 

Well, these are HW questions so I am not sure where they came from. I am using Sedra and Smith 7th edition but I dont see an explanation for them.
Your explanation makes sense. Thanks!

 

in the diagrams below, what does it mean when the dot for example Vb is filled in with black and Vin is not?

There's no meaningful difference. It could be a style used in the reference.

 

Looking at the diagram, you can see external connections having the open dot. Internal connections having the filled dots. Internal and external referenced to the circuit board. They are also variable.

That is my observation only, not a standard.