Results 1 to 3 of 3

Thread: integration using substitution

  1. #1
    New Member
    Join Date
    Feb 2018
    HSC
    2018
    Gender
    Male
    Posts
    10
    Rep Power
    1

    integration using substitution

    Hi all,

    Could I have help with


    ∫(limits 1 and -3) dx/√(x+3) using x=u^2-3

  2. #2
    Loquacious One
    Join Date
    Feb 2009
    HSC
    N/A
    Gender
    Male
    Posts
    3,689
    Rep Power
    9

    Re: integration using substitution

    Quote Originally Posted by cos16mh View Post
    Hi all,

    Could I have help with


    ∫(limits 1 and -3) dx/√(x+3) using x=u^2-3







    Why not use the Drongoski Method (if question does not insist on the substitution method!)?
    Last edited by Drongoski; 13 Apr 2018 at 5:32 PM.
    1-on-1 Maths Tutoring(IB & HSC): Epping, Beecroft, Eastwood, Carlingford & Beyond
    IB: Maths Studies, Maths SL & Maths HL; HSC: 2U, 3U & 4U
    Highly Qualified & Highly Experienced. Estimated ATAR > 9.995
    There are IB Maths Tutors and there are IB Maths Tutors.

  3. #3
    Traveller from the North fan96's Avatar
    Join Date
    May 2017
    HSC
    2018
    Gender
    Male
    Location
    NSW
    Posts
    192
    Rep Power
    1

    Re: integration using substitution



    Let , then

    The integral becomes



    (you can choose either or , it doesn't change the answer)



    ()

    and the integral should be simple from there...

    But another way is to recognise that we can integrate this by inspection:



    Last edited by fan96; 13 Apr 2018 at 3:04 PM.
    HSC 2018 - [English Adv.] • [Maths Ext. 1] • [Maths Ext. 2] • [Chemistry] • [Software Design and Development]

    1(3√3) t2 dt cos(3π/9) = log(3√e) | Integral t2 dt, From 1 to the cube root of 3. Times the cosine, of three pi over nine, Equals log of the cube root of e.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •