1. evaluating why is it important for citizens to understand
the investigative and oversight powers of congress? provide an
example.

The main aim and objective of the oversight powers of the congress is to avoid deceit, abuse, protecting the rights and duties exercised by the Government officials and safeguarding that no division of the Government become tyrannical.  

Hearings, long deliberations and investigations, getting reports directly from the president, conducting impeachment proceedings are the forms in which the congress oversights are conducted.

Based on the constitutional mandate ‘necessary and proper’, congress has all powers to scrutinize the federal agencies. Subcommittee of the Senate discovered corruption and malpractices where undertaken under the presidentship of Henry Truman. Special white house committee was prearranged in order to investigate confirmations of corruption.  

i see, would you mind putting it as one?