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1.                 From German - English Ding/FreeDict dictionary ver. 1.9-fd1:
                   
   
   
                   
                     
   Cosinus /kˈoːziːnˌʊs/ (cos /kˈoːs/) <masc, n, sg>
    [math.] cosine function <n>, cosine <n>cos,  /kˈoːs/
            Note: circular function
      Synonyms: Kosinusfunktion, Kosinus
            Note: Winkelfunktion