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Functions Question

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Dania:
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.

nid404:
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

Dania:
As always, thank you. :)

S.M.A.T:

--- 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

--- End quote ---

+rep for the fat cat :D

nid404:
You're welcome :)

thanks asif...and congrats ;)

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