Question
For 1985 through 1996, the number, C (in thousands), of videos rented each year in Moose Jaw can be modeled by C= 0.069(t^3+4t^2+37t+600) where t=0 represents 1990. During which year are 60.4 thousand movies projected to be rented?
Could someone please show me the steps to this problem?
Could someone please show me the steps to this problem?
Answers
Steve
You have the equation. Just solve for t:
C= 0.069(t^3+4t^2+37t+600)
60.4 = 0.069(t^3+4t^2+37t+600)
875.36 = t^3+4t^2+37t+600
t^3 + 4t^2 + 37t - 275.36 = 0
Cubics are hard to solve, but there are many online polynomial solvers. We get
t = 3.99, or just 4.
So, it looks like 1994 is the year you want.
Note: 4 is an exact root of
t^3 + 4t^2 + 37t - 276 = 0
which could have been found using trials of synthetic division.
C= 0.069(t^3+4t^2+37t+600)
60.4 = 0.069(t^3+4t^2+37t+600)
875.36 = t^3+4t^2+37t+600
t^3 + 4t^2 + 37t - 275.36 = 0
Cubics are hard to solve, but there are many online polynomial solvers. We get
t = 3.99, or just 4.
So, it looks like 1994 is the year you want.
Note: 4 is an exact root of
t^3 + 4t^2 + 37t - 276 = 0
which could have been found using trials of synthetic division.