some H2 maths qns

• jiaxing2

  10 Jan 09, 18:17

  hie hie...need some help here...

  1) McClaurian Seris

  2 + X + X^3/3! + 2X^4/4! + X^5/5! + X^7/7! + 2X^8/8!+....=

  2) Parametric curve....Can use GC to draw...if so how do we set the range...

  Thanks in advance

  Jiaxing

• eagle

  10 Jan 09, 19:26

  1)

  

  f(0) = 2
  f'(1) = 1
  f''(x) = 0
  f'''(x) = 1
  f''''(x) = 2
  f""'(x)=1

  and so on

  Note that there's a pattern, 2101, 2101
  
  f(x) = 2 + x + x^3/3! + 2x^4/4! + x^5/5! + x^7/7! + 2x^8/8! +....
  = (1 + x + x^2/2! + x^3/3! + x^4/4! + x^5/5! + x^6/6! + x^7/7! + x^8/8! + ...) + (1 - x^2/2! + x^4/4! - x^6/6! + x^8/8! - ... )
  

  Do check :D

   

  (2) Which GC are you using?

• wee_ws

  10 Jan 09, 20:20

  Hi,

    If you are using TI, press "WINDOW". Then provide values for "Tmin" and "Tmax".

    Thanks!

  Cheers,
  Wen Shih

• jiaxing2

  11 Jan 09, 00:12

  But still got the factorials leh....

  I was teaching someone when i encountered this qn..basic mastery nia...i tio stuck damn long..thought that it was a typo...if not the answer is kind of complicated

  I got   2cos ( ix^2)  - i sin ( ix)...

  because dun have x^2 and x^6...so i thought it must have to do wif cos x^2...but then its 2 times and more positive...i introduced the i....

  then got all the x^3 x^5...all positive some more...so not only need a i to convert all to same sign...need to divide i to remove the i that i introduced...

  anyway i figured this only after his lesson...and i tink he haven even learn complex numbers...

   

  but i dun tink they will set such ridiculous qn...

  Regarding the GC...

  i got it le...thanz for the help

• eagle

  11 Jan 09, 00:53

  Hi Jiaxing... I was careless... Changed it... Do check again.

  Nice question... Put it on ExamWorld liao.

• jiaxing2

  11 Jan 09, 09:29

  i see...nicely done...

  thanz

  jia xing