A drug is administered intravenously for pain. The function
f(t)=90 - 52 ln (1 + t), 0<t<4 gives the number of units of the drug in the body after t hours.
a. What was the initial number of units of the drug administered?
b. How much is present after 2 hours.
c. Draw the graph of f.
In part a, you substitute t for 0. So you have 90-52 ln (1 + 0). and i know that Ln1 aways = 0 . So 90-52n(1) = 90. i don't know just doesn't sound right to me for some reason. Then you plug in 2 for t. I have a feeing there's some set method for answering this kind of equation but it evades me.
Your method is correct. Why would you doubt it?
Originally Posted by fezz349
fezz349, you are almost there;
f(t)=90 - 52 ln (1 + t), 0<t<4
a) for t = 0 hour,
f(0) = 90 - 52 ln(1 +0) = 90 - 0 = 90 units of drug present
b) for t = 2 hours;
f(2) = 90 - 52 ln(1 + 2)
= 90 - 52 ln 3
= 90 - 52(1.0986)
= 90 - 57.13
= 32.87 units of drug remaining
c) See below,
alright thanks guys, it just seemed a little too straightforward, i guess every question isn't trying to trick u