Integration qn

• ^tamago^

  25 Oct 07, 20:38

  
  
  It looks easy but somehow I forgot what to sub liao.
• limywv

  25 Oct 07, 21:02

   

   

   

   

  
  
• ^tamago^

  25 Oct 07, 21:31

  Originally posted by limywv:

  it should be
  integrate(3-2x^2)^0.5
  
  = -2/6(3-2x^2)^1.5 + c
  
  =-1/3 (3-2x^2)^1.5 + c

  where got liddat wans it works for 2x but not for 2x².
  
  
  
  But,
  
  
  ok i've got the answer (as below) but the methods seems tedious.
  
  
• teraexa

  25 Oct 07, 21:33

  I would try integrating by parts.
• club18

  25 Oct 07, 21:34

  Originally posted by teraexa:

  I would try integrating by parts.

  confirm not.
• angelfairy

  25 Oct 07, 21:39

  hmm on closer inspection doesn't seem like it
• angelfairy

  25 Oct 07, 21:50

  factorize the 3 out and sub sqrt(2x/3) = sin theta
• tanjun

  25 Oct 07, 22:02

  sigh!! always careless. so deleted
  
• limywv

  25 Oct 07, 22:04

   

   

   

   

  
  
• tanjun

  25 Oct 07, 22:05

  deleted cos of carelessness.
• ^tamago^

  25 Oct 07, 23:38

  Finally done. Maths C (9233) J83/P1/Q20.
  
  
• teraexa

  26 Oct 07, 21:00

  Originally posted by club18:

  confirm not.

  told you liao =)
• tanjun

  26 Oct 07, 21:43

  using substitution method
  
  
• ^tamago^

  27 Oct 07, 01:34

  tanjun i was there but i gave up eventually. good one.
• tanjun

  27 Oct 07, 11:11

  Originally posted by ^tamago^:

  tanjun i was there but i gave up eventually. good one.

  lol. Thanks. I was careless for both the substitution part and by parts. My maths is really rusty after not practising for 2 yrs.
• Hocklez

  27 Oct 07, 11:20

  tamago still taking a lvl meh?
• Master -_-

  27 Oct 07, 11:22

  use Word to type and then print screen?
• ^tamago^

  27 Oct 07, 11:25

  Originally posted by tanjun:

  lol. Thanks. I was careless for both the substitution part and by parts. My maths is really rusty after not practising for 2 yrs.

  Mine also. This one requires a bit of inconventional thinking and really caught me by surprise.
• ^tamago^

  27 Oct 07, 11:26

  Originally posted by Hocklez:

  tamago still taking a lvl meh?

  yeah. havent take leh.
• Hocklez

  27 Oct 07, 11:28

  Originally posted by ^tamago^:

  yeah. havent take leh.

  ..... i thought taken last yr already...
• Yaimster

  27 Oct 07, 20:17

  Integration through the use of our own substitution is no longer in the H2 Maths syllabus. They would give you explicit hints to solve for that.
  
  So definately integration by parts for me
• HyuugaNeji

  27 Oct 07, 20:56

  Originally posted by Yaimster:

  Integration through the use of our own substitution is no longer in the H2 Maths syllabus. They would give you explicit hints to solve for that.
  
  So definately integration by parts for me

  I dont think you can solve this question by integration by parts.
• eagle

  27 Oct 07, 21:03

  Originally posted by HyuugaNeji:

  I dont think you can solve this question by integration by parts.

  tamago has done it using by parts
  
  check above posts
• HyuugaNeji

  27 Oct 07, 21:21

  Originally posted by eagle:

  tamago has done it using by parts
  
  check above posts

  thanks...nowsaday my maths kns already.
• tanjun

  27 Oct 07, 22:33

  lol. The by parts method is really unexpected.
  
  
  
  Try this question. Very interesting too. Have to use tamago method to solve it.