inexact vs invalid

inexact

adj
  • Imprecisely or indefinitely conceived or stated. 

  • having a path-dependent integral 

  • Imperfectly conforming; exceeding or falling short in some respect. 

invalid

adj
  • Not valid; not true, correct, acceptable or appropriate. 

  • Suffering from disability or illness. 

  • Intended for use by an invalid. 

verb
  • To make invalid or affect with disease. 

  • To exempt from (often military) duty because of injury or ill health. 

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