Results 1 to 3 of 3

Thread: Help with problem

  1. September 19th 2008, 12:49 PM #1
    sam11235
    sam11235 is offline
    Banned
    Joined
    Sep 2008
    Posts
    1

    Help with problem

    We just started a new unit and the instructor hasnt explain how to do this even thoug i can tell its simple

    Find f '(a).
    f(x) = √(3x + 1 )
    Follow Math Help Forum on Facebook and Google+
  2. September 19th 2008, 01:13 PM #2
    Matt Westwood
    Matt Westwood is offline
    Super Member Matt Westwood's Avatar
    Joined
    Jul 2008
    From
    Reading, UK
    Posts
    732
    f'(x) = \frac {3} {2 \sqrt {3x + 1}}
    Follow Math Help Forum on Facebook and Google+
  3. September 19th 2008, 03:19 PM #3
    Jhevon
    Jhevon is offline
    is up to his old tricks again! Jhevon's Avatar
    Joined
    Feb 2007
    From
    New York, USA
    Posts
    11,663
    Thanks
    3
    Note that Matt's answer comes from writing the function as (3x + 1)^{\frac 12} and applying the chain rule

    the chain rule says: \frac d{dx}f(g(x)) = f'(g(x)) \cdot g'(x)

    here, f(x) = x^{\frac 12} and g(x) = 3x + 1
    Follow Math Help Forum on Facebook and Google+
« Limit Proofs (Sup and Inf) | Please help - Stationary points »

Search Tags


/mathhelpforum @mathhelpforum