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Use the definition of continuity and the properties of limits to show that (Picture Provided Below)

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  • kudzordzifrancis


    Answer:

    Lim_{x \to 5}f(x)=f(5).

    Step-by-step explanation:

    The given function is

    f(x)=\frac{x^2-49}{(x^2+6x-7)(x^2+14x+49)}.

    We can factor an rewrite for easy evaluation;

    f(x)=\frac{(x-7)(x+7)}{(x-1)(x+7)(x+7)^2}.

    f(x)=\frac{(x-7)}{(x-1)(x+7)^2}.

    Let us plug in 5.

    f(5)=\frac{(5-7)}{(5-1)(5+7)^2}.

    f(5)=\frac{-2}{576}.

    f(5)=-\frac{1}{288}.

    Let us find the Left Hand Limit;

    Lim_{x \to 5^-}f(x)=\frac{(5-7)}{(5-1)(5+7)^2}=-\frac{1}{288}.

    Now the Right Hand Limit;

    Lim_{x \to 5^+}f(x)=\frac{(5-7)}{(5-1)(5+7)^2}=-\frac{1}{288}.

    Since the One-Sided Limits exist and are equal;

    Lim_{x \to 5}f(x)=\frac{(5-7)}{(5-1)(5+7)^2}=-\frac{1}{288}.

    We have shown that;

    Lim_{x \to 5}f(x)=f(5).

    This is the definition of continuity.

    Hence f(x) is continuous at x=5