1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Find (f^-1) (a) if f(x)

  1. Dec 1, 2008 #1
    1. The problem statement, all variables and given/known data
    Find (f^-1) (a) if f(x) = sqrt of (x^3+x^2+x+2) and a = 4?


    2. Relevant equations
    Find (f ^-1) (a) = 1/ f ^1( f ^-1(a))


    3. The attempt at a solution
    Take Derivative
    1/2(x^3+x^2+x+2)^-(1/2)
    do I need to do chain rule?
    I am lost
    this problem can help me pass the class
    plz help
     
  2. jcsd
  3. Dec 1, 2008 #2

    Mark44

    Staff: Mentor

    This problem has nothing to do with derivatives or the chain rule or reciprocals.
    [tex]x = f^{-1}(a) \iff a = f(x)[/tex]

    So basically, what you need to do is solve the equation [tex]4 = \sqrt{x^3 + x^2 + x + 2}[/tex]

    BTW, this doesn't make any sense at all: (f ^-1) (a) = 1/ f ^1( f ^-1(a))
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook




Loading...