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: Differentiate Problem.

  1. Jul 22, 2010 #1
    1. The problem statement, all variables and given/known data

    Differentiate.

    f(x) = (x) (square root of (x2+5))

    2. Relevant equations



    3. The attempt at a solution

    f(x) = (x) (square root of (x2+5))

    =(x)(x2+5)1/2

    f'(x)=(x)1/2(x2+5)-1/2(2x)+(1)(x2+5)

    =x3/(x2+5)1/2+(x2+5)1/2

    I'm having problems simplifying. The answer in the back of the book is 2x^2 + 5 / Square root of x^2+5..
     
    Last edited: Jul 22, 2010
  2. jcsd
  3. Jul 22, 2010 #2

    Mark44

    Staff: Mentor

    The above is correct, but you made a mistake in the next line.
    This should be [tex]\frac{x^2}{(x^2 + 5)^{1/2}} + (x^2 + 5)^{1/2}[/tex]

    You can take a factor of 1/(x2 + 5)1/2 from both terms above.
     
  4. Jul 22, 2010 #3
    Thank You! Thank You!
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook