coercive vs compulsory

coercive

adj
  • Displaying a tendency or intent to coerce. 

  • Such that the ratio of |F(x)| to x approaches infinity as x approaches infinity. 

compulsory

adj
  • Having the power of compulsion; constraining. 

  • Required; obligatory; mandatory. 

noun
  • Something that is compulsory or required. 

How often have the words coercive and compulsory occurred in a corpus of books? (source: Google Ngram Viewer )