Results 1 to 2 of 2

Math Help - Calculus with Integration

  1. #1
    Newbie
    Joined
    Mar 2008
    Posts
    19

    Calculus with Integration

    Hi I got urgent problems with this assignment involving integration

    One is substituting t into the equation.

    Limits [1, 10] Integrate (1*x^-1/2)* log*x^1/2 dx
    Using x = t^2.

    Firstly I worked out dx = 2t and substitute x and dx to get
    (1/t)*logt 2t

    Then I think that integrating that will get me

    1/2[Ln|t|*1/t] with limits 1 and 10 but I got huge doubts at this stage.

    ==============================================

    And this one involves Trigionomic Substitution.

    And Limits ["pi"/4, "pi"/2] Integrate dx/sinx where you use t = tan (x/2)
    Only thing cae to mind was identities like tan(x/2) = sin(x/2)/cos(x/2) but didnt get far on this one either

    Could you guys help me out pls?

    Thx
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Behold, the power of SARDINES!
    TheEmptySet's Avatar
    Joined
    Feb 2008
    From
    Yuma, AZ, USA
    Posts
    3,764
    Thanks
    78
    Quote Originally Posted by NeloAngelo View Post
    Hi I got urgent problems with this assignment involving integration

    One is substituting t into the equation.

    Limits [1, 10] Integrate (1*x^-1/2)* log*x^1/2 dx
    Using x = t^2.

    Firstly I worked out dx = 2t and substitute x and dx to get
    (1/t)*logt 2t

    Then I think that integrating that will get me

    1/2[Ln|t|*1/t] with limits 1 and 10 but I got huge doubts at this stage.

    ==============================================

    And this one involves Trigionomic Substitution.

    And Limits ["pi"/4, "pi"/2] Integrate dx/sinx where you use t = tan (x/2)
    Only thing cae to mind was identities like tan(x/2) = sin(x/2)/cos(x/2) but didnt get far on this one either

    Could you guys help me out pls?

    Thx
    after sub you should get

    \int_{1}^{\sqrt{10}}\frac{1}{t}\log(t)(2t)dt=2\int  _{1}^{\sqrt{10}}\log(t)dt

    try integration by parts and note: \log{t}=\frac{ln(t)}{ln(10)}
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Calculus - Integration
    Posted in the Calculus Forum
    Replies: 3
    Last Post: January 10th 2010, 05:23 PM
  2. Calculus - Integration
    Posted in the Calculus Forum
    Replies: 18
    Last Post: January 10th 2010, 06:24 AM
  3. [Calculus AB] Integration
    Posted in the Calculus Forum
    Replies: 1
    Last Post: March 24th 2009, 04:25 AM
  4. Calculus 2 Integration
    Posted in the Calculus Forum
    Replies: 2
    Last Post: April 17th 2008, 02:28 PM
  5. calculus integration
    Posted in the Calculus Forum
    Replies: 1
    Last Post: March 8th 2008, 07:32 PM

Search Tags


/mathhelpforum @mathhelpforum