Results 1 to 4 of 4

Math Help - hard indefinite integral

  1. #1
    Member
    Joined
    Feb 2010
    Posts
    98

    hard indefinite integral

    Pretty confused on how to do this one

    Evaluate the indefinite integral.


    Integral =
    [NOTE: Remember to enter all necessary *, (, and ) !!
    Enter arctan(x) for , sin(x) for . ]
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Senior Member apcalculus's Avatar
    Joined
    Apr 2009
    From
    Boston
    Posts
    293
    Quote Originally Posted by tbenne3 View Post
    Pretty confused on how to do this one

    Evaluate the indefinite integral.


    Integral =
    [NOTE: Remember to enter all necessary *, (, and ) !!
    Enter arctan(x) for , sin(x) for . ]
    Set:
    u = x^3 + 1


    Note that

    x^5 = (u-1) x^2

    and that

    du = 3x^2 dx

    This should help solve for the antiderivative. Good luck!
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Member
    Joined
    Feb 2010
    Posts
    98
    Quote Originally Posted by apcalculus View Post
    Set:
    u = x^3 + 1


    Note that

    x^5 = (u-1) x^2

    and that

    du = 3x^2 dx

    This should help solve for the antiderivative. Good luck!
    still cant get it
    Follow Math Help Forum on Facebook and Google+

  4. #4
    MHF Contributor
    skeeter's Avatar
    Joined
    Jun 2008
    From
    North Texas
    Posts
    11,623
    Thanks
    428
    Quote Originally Posted by tbenne3 View Post
    still cant get it
    as clearly stated earlier ...

    u = x^3+1

    du = 3x^2 \, dx

    x^3 = u - 1

    \int x^5 \sqrt[3]{x^3+1} \, dx

    \frac{1}{3} \int x^3 \sqrt[3]{x^3+1} \cdot 3x^2 \, dx

    substitute ...

    \frac{1}{3} \int (u-1) \sqrt[3]{u} \,\, du

    finish it.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. indefinite integral
    Posted in the Calculus Forum
    Replies: 11
    Last Post: July 13th 2011, 08:47 AM
  2. indefinite integral
    Posted in the Calculus Forum
    Replies: 1
    Last Post: October 22nd 2010, 04:22 PM
  3. [SOLVED] Indefinite Integral help
    Posted in the Calculus Forum
    Replies: 4
    Last Post: July 11th 2010, 06:02 PM
  4. Hard indefinite integrals
    Posted in the Calculus Forum
    Replies: 6
    Last Post: July 28th 2009, 03:08 AM
  5. Lost on Hard Substitution Indefinite Integral
    Posted in the Calculus Forum
    Replies: 5
    Last Post: April 14th 2009, 08:36 AM

Search Tags


/mathhelpforum @mathhelpforum