SOLUTION: Pseudoephedrine hydrochloride is an allergy medication. The polynomial function L(t) = 0.03t^4 + 0.4t^3 - 7.3t^2 + 23.1t where 0< or equal to t

If you need immediate math help from PAID TUTORS right now, click here. (paid link)
Click here to see ALL problems on Linear Equations And Systems Word Problems

Question 57254This question is from textbook Applied College Algebra
: Pseudoephedrine hydrochloride is an allergy medication. The polynomial function
L(t) = 0.03t^4 + 0.4t^3 - 7.3t^2 + 23.1t
where 0< or equal to t < or equal to 5, models the levels of pseudoephedrine
hydrochloride, in milligrams, in the bloodstream of a patient t hours after 30 milligrams of the medication have been taken.
At what times, to the nearest minute, does the level of pseudoephedrine hydrochloride in the bloodstream reach 12 milligrams?This question is from textbook Applied College Algebra

Answer by stanbon(48568) (Show Source):
You can put this solution on YOUR website!
L(t) = 0.03t^4 + 0.4t^3 - 7.3t^2 + 23.1t
12= 0.03t^4 + 0.4t^3 - 7.3t^2 + 23.1t
0.03t^4 + 0.4t^3 - 7.3t^2 + 23.1t-12=0
Graphing it with a TI-83 I find zeroes at
t=0.6467...;3.6304...;6.93929...
There is another zero but I cannot find it.
Cheers,
Stan H.

SOLUTION: Pseudoephedrine hydrochloride is an allergy medication. The polynomial function L(t) = 0.03t^4 + 0.4t^3 - 7.3t^2 + 23.1t where 0< or equal to t < or equal to 5, models the levels