Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Help chain rule/tangent stuff

  1. Dec 13, 2004 #1
  2. jcsd
  3. Dec 13, 2004 #2
    chain rule states that if [itex]f(x)=f(u(x))[/itex] then


    as examples, first one




    given that




    then chain rule states


    substituting [itex]u[/itex]


    in the next one, you are almost there... all you have to do is factorize [itex](6x^2-5)^4(2x-1)^3[/itex]

    the third one you can do it by calculating [itex]y=y(x)[/itex] and [itex]x=x(y)[/itex] and then differentiate ie

    [tex]y(x)=\frac{x}{4}(3 \pm \sqrt{5})[/tex]

    or by implicit differentiation.

    The next one you already have it, the only thing you need to do is evaluate [itex]y'(2)[/itex] and [itex]y'(3)[/itex] then use the fact that

    in the last two you use the fact that [itex](f\circ g)(x)=g(f(x))[/itex] be carefull tough, you are doing it wrong in the last one (watch the root).
    Last edited: Dec 13, 2004
  4. Dec 14, 2004 #3
    Thaaaaank you

    Thaaaaank you :biggrin:
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook