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Old 08-13-2003, 03:18 AM   #5
Bruce The Aussie
Fzoul Chembryl
 

Join Date: March 2, 2001
Location: Chaotica (london,england)
Age: 39
Posts: 1,798
Quote:
Originally posted by Vaskez:
In words: f(x) is a function acting on the unknown x (representing any unknown value) that transforms this unknown value into itself squared - itself + 3.

note: a2 means "a squared" but I can't do superscript here

So all you have to do to apply this function to any other value is substitute this other value in the place of x.
So if we want to work out f(a+h) simply substitute (a+h) everywhere where there is x in the definition of f(x)

f(x) = x2 - x + 3
so
f(a+h) = (a+h)2 - (a+h) + 3
=> (a+h)*(a+h) - (a+h) + 3 (multiply out)
=> a2 + ah + ha + h2 -a -h + 3
=> a2 + 2ah + h2 -a -h +3

and that's where the 2ah comes from, simple as that
hellohello

just quote this and you can find out how to do superscript [img]tongue.gif[/img]

cool...i've been trying to understand this for my Pure 1 exams this november....i don't like it much.....

[ 08-13-2003, 03:19 AM: Message edited by: Bruce The Aussie ]
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