Results 1 to 2 of 2

Math Help - logarithm/exponential word problem

  1. #1
    Junior Member
    Joined
    Apr 2010
    Posts
    43

    logarithm/exponential word problem

    The value V of a certain automobile that is t years old can be modeled by
    V(t)=14,044(0.8)^t.
    According to the model, when will the car be worth:
    (a) $8000?
    (b) $7000?
    (c) $1000?

    Answers:
    (a) 2.5 years
    (b) 3.1 years
    (c) 11.8 years

    It says I need to rewrite the problem in logarithmic form, how would I do this?
    log 8000 = log 14044(.8)^t?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Master Of Puppets
    pickslides's Avatar
    Joined
    Sep 2008
    From
    Melbourne
    Posts
    5,236
    Thanks
    28
    Quote Originally Posted by desiderius1 View Post
    The value V of a certain automobile that is t years old can be modeled by
    V(t)=14,044(0.8)^t.
    According to the model, when will the car be worth:
    (a) $8000?
    (b) $7000?
    (c) $1000?

    Answers:
    (a) 2.5 years
    (b) 3.1 years
    (c) 11.8 years

    It says I need to rewrite the problem in logarithmic form, how would I do this?
    log 8000 = log 14044(.8)^t?
    Your answers are correct.

    For log form I would suggest this as a function for making t the subject

    V=14044(0.8)^t

    \frac{V}{14044}= (0.8)^t

    \log_{0.8}\frac{V}{14044}= t

     t= \log_{0.8}\frac{V}{14044}
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 2
    Last Post: June 9th 2011, 09:54 AM
  2. Logarithm Word Problem
    Posted in the Algebra Forum
    Replies: 2
    Last Post: July 23rd 2010, 08:55 AM
  3. Replies: 5
    Last Post: April 20th 2010, 05:35 PM
  4. exponential word problem
    Posted in the Algebra Forum
    Replies: 1
    Last Post: June 8th 2009, 07:49 PM
  5. exponential word problem
    Posted in the Pre-Calculus Forum
    Replies: 1
    Last Post: December 9th 2008, 03:00 PM

Search Tags


/mathhelpforum @mathhelpforum