Results 1 to 2 of 2

Math Help - Basic Pullback Question

  1. #1
    Member
    Joined
    Sep 2009
    From
    Minnesota
    Posts
    80
    Thanks
    8

    Basic Pullback Question

    The book I'm using asks:

    Let φ : R → R be given by φ(t) = et . Let x be the usual coordinate function on R. Show that φ*x = ex .

    I can't figure this out and I don't understand why - what is the 'usual coordinate function' on R? I at first interpreted it as f(x) = x, but that doesn't make sense:

    f : R → R given by f(x) = x. Then composing f with φ (the definition of pullback) gives φ*x = f(φ(t)) = et

    Am I just doing something very stupid here?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Senior Member
    Joined
    Mar 2010
    From
    Beijing, China
    Posts
    293
    Thanks
    23

    Re: Basic Pullback Question

    φ*x=φ*f(x)=f(φ(x))=φ(x)=e^x
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 2
    Last Post: March 6th 2013, 09:58 PM
  2. pullback is not the product
    Posted in the Advanced Math Topics Forum
    Replies: 0
    Last Post: November 23rd 2011, 03:08 PM
  3. Replies: 3
    Last Post: September 21st 2011, 07:21 PM
  4. property of pullback
    Posted in the Differential Geometry Forum
    Replies: 0
    Last Post: June 10th 2010, 11:09 AM
  5. Self-intersection of the pullback of a hyperplane
    Posted in the Advanced Algebra Forum
    Replies: 1
    Last Post: November 3rd 2008, 07:28 AM

Search Tags


/mathhelpforum @mathhelpforum