AdminKeymaster

December 8, 2018 at 7:04 am

Post count: 678

The population of a town can be found by the formula P = 3200e^{-0.02t}, where t represents the number of years elapsed since 1980. What is the annual rate of decrease of the towns population during the decade 1980 – 1989? |

P = 3200e^{-0.02 x 0 }= 3200e^{0} = 3200 × 1 = 3200 |
in 1980, t = 0 because it is the beginning of the time period substitute t = 0 into the equation the “e” button can be found on your calculator above the ln button. to use it, press shift ln and you should see ee and you put the 0 in the square |

P = 3200e^{-0.02 x 10 }= 3200e^{-0.2 }= 2619.938 |
in 1989, t = 10 substitute t = 10 into the equation |

200 – 2619.938 = 580.06 |
find the decrease |

580.06 ÷ 10 = 58 ∴ decreasing by 58 per year |
to find the average over 10 years, divide the decrease by 10 |