The effectiveness of a certain medical injection is modeled by E(t)=0.01t(140−t)
, where t is time in minutes and E is a measure of concentration in the bloodstream. Effectiveness readings above 16
are satisfactory and readings above 63
are dangerous.
Step 1 of 2 : How many minutes after the first injection are the readings satisfactory and how many minutes after the first injection do they become too low? Express your answer in exact form or as a decimal number rounded to two decimal places.
