They both have the same roots(germanic?), just like german. Of course there will be many similarities, but the languages cannot be named 'copies' in my opinion. All of them have their own story and their own influences.
Well German is a Bastardized Language, so its just a bunch a different languages that all came together to form one. Im pretty sure Norwegian is also a Bastardized Language; it has roots in the Scandinavian area.