decided vs invariant

decided

adj
  • Determined; resolute. 

  • Clear; unmistakable. 

noun
  • A voter etc. who has reached their decision. 

invariant

adj
  • not varying; constant 

  • Neither covariant nor contravariant. 

  • Unaffected by a specified operation (especially by a transformation) 

noun
  • An invariant quantity, function etc. 

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