negation - When I ask a simple question should I ask it in negative form?

My textbook is prompting me to ask questions:

"Don't you want to see a movie?"
eiga o mimasen ka?

"Don't you want to eat dinner?"
bangohan o tabemasen ka?

I'm wondering if I should be asking these types of negative questions instead something like this:

"Do you want to see a movie?"
eiga o mimas ka?

etc...

Answer

Questions can be asked in either positive or negative. They only vary by politeness (with the latter being more so).

映画{えいが}を見{み}ませんか。
映画を見ますか。

These are two nearly identical ways of asking the same thing (Do you want to see a movie?). The only difference is that the former is slightly more polite.

Also, unlike English, responses are reversed when the question is in the negative. What I mean by that is:

映画{えいが}を見{み}ますか。 (Do you want to see a movie?)
はい (=Yes, I do want to see a movie)
いいえ (=No, I don't want to see a movie)

However:

映画{えいが}を見{み}ませんか。(Don't you want to see a movie?)
はい (=No, I don't want to see a movie)
いいえ (=Yes, I do want to see a movie)