If f(x) is an even function, which statement about the graph of f(x) must be true?

Sorry guys but as you have a small brain

Ricky takes out a $31,800 student loan to pay his expenses while he is in college. after graduation, he will begin making payments of $190.66 per month for the next 30 years to pay off the loan. how much more will ricky end up paying for the loan than the original value of $31,800? ricky will end up paying $ more than he borrowed to pay off the loan.

Does the point (1, sqrt 7) lie on circle shown.