ascertain

establish after a calculation, investigation, experiment, survey, or study; "find the product of two numbers"; "The physicist who found the elusive particle won the Nobel Prize"

After encephalitis deaths, Odisha Health Minister has directed officials to ascertain toxic content in litchi fruit being sold in the state.

They ascertained whether the newspaper reports are accurate.Ascertain the facts about the case.They are trying to ascertain what has actually happened.