problematic vs unconfirmed

problematic

adj
  • Not settled, uncertain, of uncertain outcome; debatable, questionable, open to doubt. 

  • Difficult to overcome, solve, or decide. 

  • Contributing (especially if subtly) to discrimination (such as racism, sexism, homophobia, transphobia, or ageism). 

  • a problematic analysis 

noun
  • A problem or difficulty in a particular field of study. 

unconfirmed

adj
  • Not finally established, settled or confirmed. 

  • Not having undergone the ritual of confirmation. 

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