题目
题目

MAT135H5_F25_ALL SECTIONS 1.5 Preparation check

多重下拉选择题

Lisa has a headache and takes some acetaminophen (perhaps Tylenol) at time 𝑡 = 0 . The amount 𝐴 (in mg) left in Lisa's body at time 𝑡 (in hours) can be modeled by: 𝐴 ( 𝑡 ) = 500 𝑒 𝑡 ln ⁡ 0.8     a) What was the amount of acetaminophen Lisa took at time 𝑡 = 0 ?  [ Select ] 0.8 mg 625 mg 400 mg 500 mg 800 mg b) How many mg is left in Lisa's body after 4 hours? Use a calculator and round to 1 decimal place if needed.  [ Select ] 190.5 mg 500 mg 368.4 mg 400 mg 204.8 mg c) At what time is only 100 mg left in Lisa's body? Use a calculator and round to 1 decimal place if needed. (Answer in hours. Do NOT convert to minutes.) [ Select ] After 7.1 hours After 6.5 hours After 8.1 hours After 6.3 hours After 7.2 hours

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思路分析
We start by restating the problem components so each part is clear. - The model for the acetaminophen amount is A(t) = 500 * e^{t * ln(0.8)} which is equivalently A(t) = 500 * (0.8)^t. - Part a asks for A(0), i.e., the initial amount Lisa took at t = 0, with options: 0.8 mg, 625 mg, 400 mg, 500 mg, 800 mg. - Part b asks for A(4) in mg, with options: 190.5 mg, 500 mg, 368.4 mg, 400 mg, 204.8 mg. - Part c asks for the time when A(t) = 100 mg, i.e., solving 500*(0.8)^t = 100, with options: After 7.1 hours, After 6.5 hours, After 8.1 hours, After 6.3 hours, After 7.2 hours. Now, evaluate each option and explain why it is correct or incorrect. Part a: What was the amount at t = 0? - Option: 0.8 mg — Incorrect. The model start......Login to view full explanation

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