Results 1 to 2 of 2
Like Tree1Thanks
  • 1 Post By HallsofIvy

Math Help - Factoring exponents that differ by an integer

  1. #1
    Junior Member
    Joined
    Jan 2013
    From
    adelaide
    Posts
    26

    Exclamation Factoring exponents that differ by an integer

    Factoring exponents that differ by an integer-image.jpg

    Hi guys sending this on my phone at work please tell me if its too small and ill type it out. This is the full working that I have for a derivative problem which I was fine with until the very last step. When I did it my last step involved putting the first term back into a square root and the same with the last term except in the denominator under 1.
    Some factoring has happened here that I don't understand, can someone please explain to me what has happened and why between the last 2 steps? (The denominator at bottom has been cut out on uploading, it's a 3)
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor

    Joined
    Apr 2005
    Posts
    15,602
    Thanks
    1421

    Re: Factoring exponents that differ by an integer

    The "last two steps" are just combining like terms. The derivative of x(x+ 3)^{1/2} is, as you say, (x+ 3)^{1/2}+ (1/2)x(x+ 3)^{-1/2}. You can, then, factor (x+ 3)^{-1/2}. Of course, (x+ 3)^{1/2}= (x+ 3)(x+ 3)^{-1/2} so that gives (x+ 3)^{-1/2}(x+ 3- (1/2)x). That denominator that was cut off should be a 2, not a 3. And x- (1/2)x= (1/2)x so that is equal to (x+ 3)^{-1/2}((1/2)x+ 3)
    Thanks from camjerlams
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Solving for Non-Integer Exponents - Help
    Posted in the Algebra Forum
    Replies: 4
    Last Post: January 7th 2010, 03:10 PM
  2. Factoring with exponents
    Posted in the Algebra Forum
    Replies: 6
    Last Post: December 17th 2009, 10:53 AM
  3. Factoring polynomials with exponents
    Posted in the Algebra Forum
    Replies: 3
    Last Post: October 25th 2009, 10:42 AM
  4. Integer factoring with polynomials
    Posted in the Number Theory Forum
    Replies: 0
    Last Post: August 23rd 2009, 10:07 PM
  5. integer exponents
    Posted in the Algebra Forum
    Replies: 1
    Last Post: July 29th 2008, 04:40 AM

Search Tags


/mathhelpforum @mathhelpforum