Doctors use radioactive lodine as a tracer in diagnosing certain thyroid gland disorders This type of iodine decays in such a way that the mass remaining after t days is given by the function m t 3e 0 089t where m t is measured in grams a Find the mass at time t 0 grams b How much of the mass remains after 9 days Round your answer to three decimal places 8 972 x grams