Results 1 to 3 of 3

Thread: tangent slope of f

  1. #1
    Member
    Joined
    Sep 2011
    Posts
    118
    Thanks
    2

    tangent slope of f

    what is the tangent slope of the f(x)= $\displaystyle \frac{5}{x}$ at the point (-2, $\displaystyle \frac{-5}{2}$) using the formula lim x->a $\displaystyle \frac{f(x)-f(a)}{x-a}$
    $\displaystyle \frac{\frac{5}{x}-(-\frac{5}{2})}{x-(-2)}$

    i get two here and i am stuck
    $\displaystyle \frac{\frac{5}{x}+(\frac{5}{2})}{x+2}$
    I can see that I can potentially cancel out the (x+2)but I am not sure.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Flow Master
    mr fantastic's Avatar
    Joined
    Dec 2007
    From
    Zeitgeist
    Posts
    16,948
    Thanks
    9

    Re: tangent slope of f

    Quote Originally Posted by delgeezee View Post
    what is the tangent slope of the f(x)= $\displaystyle \frac{5}{x}$ at the point (-2, $\displaystyle \frac{-5}{2}$) using the formula lim x->a $\displaystyle \frac{f(x)-f(a)}{x-a}$
    $\displaystyle \frac{\frac{5}{x}-(-\frac{5}{2})}{x-(-2)}$

    i get two here and i am stuck
    $\displaystyle \frac{\frac{5}{x}+(\frac{5}{2})}{x+2}$
    I can see that I can potentially cancel out the (x+2)but I am not sure.
    The next step is

    $\displaystyle \frac{\frac{10+5x}{2x}}{x+2}$
    Follow Math Help Forum on Facebook and Google+

  3. #3
    MHF Contributor

    Joined
    Mar 2011
    From
    Tejas
    Posts
    3,546
    Thanks
    842

    Re: tangent slope of f

    remember that (a/b)/c = (a/b)(1/c) = a/(bc), to simplify the fraction.

    does x+2 divide 10+5x evenly?
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 6
    Last Post: Jan 12th 2011, 02:38 PM
  2. slope of tangent
    Posted in the Calculus Forum
    Replies: 4
    Last Post: Oct 28th 2009, 04:01 PM
  3. Secant Line Slope and Tangent Line Slope
    Posted in the Calculus Forum
    Replies: 3
    Last Post: Aug 26th 2009, 05:40 PM
  4. Slope of tangent #1
    Posted in the Pre-Calculus Forum
    Replies: 20
    Last Post: Aug 2nd 2009, 06:47 PM
  5. Tangent slope
    Posted in the Pre-Calculus Forum
    Replies: 3
    Last Post: Feb 15th 2008, 09:37 AM

Search Tags


/mathhelpforum @mathhelpforum