« previous next »
Pages: [1]   Go Down

Author Topic: Functions Question  (Read 876 times)

Offline Dania

  • SF Immigrant
  • **
  • Posts: 115
  • Reputation: 3838
  • Gender: Female
    • Twitter
Functions Question
« on: October 03, 2010, 06:42:24 pm »
The function h is defined by: h:x = 6x-x2 for x [is greater than or equal] to 3

Express 6x-x2 in the form a-(x-b)2, where a and b are positive constants.

How would I go about such questions? I've seen them in quite a number of past papers.
Logged
:)

nid404

  • Guest
Re: Functions Question
« Reply #1 on: October 03, 2010, 06:50:50 pm »
completing the square method.

http://en.wikipedia.org/wiki/Completing_the_square

So in this case

(x-3)2= x2-6x+9

so -x2+6x can be written as 9-(x-3)2
Logged

Offline Dania

  • SF Immigrant
  • **
  • Posts: 115
  • Reputation: 3838
  • Gender: Female
    • Twitter
Re: Functions Question
« Reply #2 on: October 03, 2010, 07:03:37 pm »
As always, thank you. :)
Logged
:)

Offline S.M.A.T

  • SF Master
  • ******
  • Posts: 1595
  • Reputation: 18522
  • Gender: Male
Re: Functions Question
« Reply #3 on: October 03, 2010, 07:09:32 pm »
Quote from: Garfield on October 03, 2010, 06:50:50 pm
completing the square method.

http://en.wikipedia.org/wiki/Completing_the_square

So in this case

(x-3)2= x2-6x+9

so -x2+6x can be written as 9-(x-3)2

+rep for the fat cat :D
Logged


"A man's life is interesting primarily when he has failed - I well know. For it's a sign that he tried to surpass himself." Clemenceau, Georges

nid404

  • Guest
Re: Functions Question
« Reply #4 on: October 03, 2010, 07:11:27 pm »
You're welcome :)

thanks asif...and congrats ;)
Logged
Pages: [1]   Go Up
« previous next »