しあわせ　〜　 日本語のノット

MNN35-5

A question phrased in the negative makes it easier for the listener to answer in the negative. And as such is more considerate / polite.
It has the same meaning as a positive question. (and most likely translated to the positive in English)

2、3日旅行をしようと思っているんですが、どこかいい所はありませんか。