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VCE Stuff => VCE Mathematics => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Mathematical Methods CAS => Topic started by: jag on February 10, 2009, 09:30:10 pm

Title: composite functions help II
Post by: jag on February 10, 2009, 09:30:10 pm: The functions f and g are defined by f : R --> R,f(x) = $x^2 - 2$ and g: {x:x more than or equal to 0} -----> , where g(x) = $\sqrt{x}$

(a) explain why g o f does not exist.
(b) Find f o g
Title: Re: composite functions help II
Post by: dekoyl on February 10, 2009, 09:40:43 pm: a) $g(f(x))$ does not exist as the range of f(x) [-2, $\infty$ ) is not within the domain of g(x) $[0,\infty)$ .
b) $f(g(x)) = x - 2$

Is that right, jag?
Title: Re: composite functions help II
Post by: jag on February 10, 2009, 10:33:31 pm: yep =]
Title: Re: composite functions help II
Post by: Mao on February 10, 2009, 11:23:54 pm: umm... this question is exactly the same as the one you posted in the other thread. I suggest you go edit the first post of the other thread [yes, you can do that, the edit button is on the right].

Locked.