Letf:Â® Â be given byf(x) =x2 - 4 . Then lim

x®-3

(x^2 - 4) = 5.

any help will be appraciated,thanks.

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- Dec 1st 2009, 02:57 PMkoko2009the formal definition of limitLet
*f*:Â® Â be given by*f*(*x*) =*x*2 - 4 . Then lim

x®-3

(*x^*2 - 4) = 5.

any help will be appraciated,thanks.

- Dec 1st 2009, 05:18 PMDrexel28$\displaystyle \left|x^2-4-5\right|=\left|x-3\right|\left|x+3\right|$. Now if we only consider a neighborhood of radius $\displaystyle 1$ (i.e. $\displaystyle 0<|x+3|<1$ then we can say that $\displaystyle |x-3|<c$ for some $\displaystyle c$ (find it). Do you get the idea?