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: Determine all primitive functions

  1. Sep 3, 2016 #1
    1. The problem statement, all variables and given/known data

    Determine all primitive functions for the function:


    2. The attempt at a solution

    When i expanded i got the primitive to be:


    But this was wrong. I am not sure I have understood the question. Help?
  2. jcsd
  3. Sep 3, 2016 #2


    Staff: Mentor

    I have moved this thread, as it is not a precalculus problem.

    Apparently the problem asks you to find all antiderivatives of 2x(x2 + 3)4. In other words, carry out this integration: ##\int 2x(x^2 + 3)^4 dx##. The answer should have a highest degree term of x10. Don't forget the constant of integration.
    Instead of expanding the binomial in parentheses, think about a simple substitution that you can do.
  4. Sep 3, 2016 #3
    One possible substitution is 2x(z)^4

    But I am not sure how to proceed from here...
  5. Sep 3, 2016 #4


    Staff: Mentor

    If z = x^2 + 3, what is dz?
    A very simple substitution will work, and you're on the right track,
    When you use substitution to evaluate an integral, you're using the chain rule in reverse.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted