Problema Solution
Solve the problem. The concentration, in parts per million, of a particular drug in a patient's blood x hours after the drug is administered is given by the function f(x) = -x^4+11x^3-24x^2+54x
How many hours after the drug is administered will it be eliminated from the bloodstream?
Answer provided by our tutors
f(x)= -x^4+11x^3-24x^2+54x. how many hours will it take the drug to be eliminated from the blood stream
-----------------
Solve -x^4+11x^3-24x^2+54x = 0 for "x":
----
Factor out "-x" to get:
-x(x^3 - 11x^2 + 24x - 54) = 0
---
Solve x^3-11x^2 + 24x -54 = 0
-----
I graphed it and found a zero at x = 9
---
9)....1....-11....24....-54
.......1......-2....6....|..0
Quotient: x^2-2x+6 has complex zeroes.
----
x = 9 is the only decent answer.