étudié

In a sentence

• Il a étudié les sciences à l'université.

  He studied sciences at the university.

  In this sentence, "étudié" is used as the past participle of "étudier," indicating an action performed by the subject in the past—specifically, the act of studying academic subjects.

• Ce raisonnement est bien étudié et logique.

  This reasoning is well thought out and logical.

  Here, "étudié" serves as an adjective describing the quality of the reasoning—implying it has been considered or explored thoroughly.

• La solution étudiée par les chercheurs semble prometteuse.

  The solution studied by the researchers appears promising.

  In this context, "étudié" functions as a past participle used in a passive construction, indicating the solution has been the object of study by someone else (the researchers).