Results 1 to 7 of 7

Math Help - function

  1. #1
    Newbie
    Joined
    Oct 2008
    Posts
    9

    function

    So they give me this

    Y=100e^(-0.076)

    Write the exponential function in the form y=ab^t. Find b accurate to four decimal places. If t is measured in years, give the percent annual growth or decay rate and the continuaous percent growth or decay rate per yer.

    Isn't it already in the form they ask me to put it in?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Super Member
    earboth's Avatar
    Joined
    Jan 2006
    From
    Germany
    Posts
    5,807
    Thanks
    116
    Quote Originally Posted by Kate182 View Post
    So they give me this

    Y=100e^(-0.076)

    Write the exponential function in the form y=ab^t. Find b accurate to four decimal places. If t is measured in years, give the percent annual growth or decay rate and the continuaous percent growth or decay rate per yer.

    Isn't it already in the form they ask me to put it in?
    I assume that you mean:

    y = 100 \cdot e^{-0.076 \cdot t} = 100 \cdot \left(e^{-0.076}\right)^t = 100 \cdot 0.9268^t
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Oct 2008
    Posts
    9
    i meant this sorry i wrote it wrong.

    y=100e^(-0.07t)
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Super Member
    earboth's Avatar
    Joined
    Jan 2006
    From
    Germany
    Posts
    5,807
    Thanks
    116
    Quote Originally Posted by Kate182 View Post
    i meant this sorry i wrote it wrong.

    y=100e^(-0.07t)
    y=100\cdot e^{-0.07t} = 100\cdot \left(e^{-0.07}\right)^t = 100\cdot 0.9324^t
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Newbie
    Joined
    Oct 2008
    Posts
    9
    How do i find the growth or decay rate then?
    Follow Math Help Forum on Facebook and Google+

  6. #6
    Super Member
    earboth's Avatar
    Joined
    Jan 2006
    From
    Germany
    Posts
    5,807
    Thanks
    116
    Quote Originally Posted by Kate182 View Post
    How do i find the growth or decay rate then?
    If t = 0 you have y = 100;

    if t = 1 you have y = 93.24.

    Thus you have an absolute decay of d(1) = 6.76

    Now calculate the relative decay:

    r = \dfrac{d(1)}{y(0)}\cdot 100

    I've got 6.76 \%
    Follow Math Help Forum on Facebook and Google+

  7. #7
    Newbie
    Joined
    Oct 2008
    Posts
    9
    So that would be the annual growth rate right?
    what about the continuous, is it the same?
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 20
    Last Post: November 27th 2012, 05:28 AM
  2. Replies: 0
    Last Post: October 19th 2011, 04:49 AM
  3. Replies: 4
    Last Post: October 27th 2010, 05:41 AM
  4. Replies: 3
    Last Post: September 14th 2010, 02:46 PM
  5. Replies: 2
    Last Post: September 2nd 2010, 10:28 AM

Search Tags


/mathhelpforum @mathhelpforum