Soon after taking an aspirin, a patient has absorbed 280 mg of the drug. After 2 hours, only 70 mg remain. Find an exponential model for the amount of aspirin in the bloodstream after t hours. HINT [See Example 2.]
f(t)=
Use your model to find the amount of aspirin in the bloodstream after 4 hours.
y = 300e^(-Bt) plug in y = 75 and t = 2 75 = 300e^(-2B) 75/300 = e^(-2B) ln(75/300) = -2B B = -ln(75/300) / 2 so B = approx 0.693300 = A(e^0) = A A = 300 . 9.4 mg left in the bloodstream after 5 hours.
