Question Word +TO-infinitive +Complement : Can this pattern be used for a direct question?

On the internet I have found some titles of articles that use the following pattern of construction:

Question word + TO-infinitive + Complement

I know that such structure fulfill different functions, but I am not certain if this same pattern can be used for direct questions. So, for instance, the following cases:

1. How to learn German on your own.
2. How to avoid eating fat.
3. What to do during an earthquake.

Are all of these examples questions? or do they belong to a different grammar category? The cases that I have found on the web never use a question mark but rather a period in the end.