Answer
$$f(x)=\frac{2}{(x-2)^2}$$
The graph is below.
Work Step by Step
(What I present here is just an example. There are other possible functions which satisfy the exercise.)
- As $\lim_{x\to2^-}f(x)=\lim_{x\to2^+}f(x)=\infty$, I would suppose that my function would have this rational form $A/B$, and in the denominator $B=(x-2)^2$ to make the function approach $\infty$ as $x\to2^-$ and $2^+$. Also $A\gt0$ to have the necessary result $\infty$.
$$f(x)=\frac{A}{(x-2)^2}$$
- As $\lim_{x\to\pm\infty}f(x)=0$:
$$\lim_{x\pm\infty}\frac{A}{(x-2)^2}=\lim_{x\pm\infty}\frac{A}{x^2-2x+1}=0$$
Remember the method that divides both numerator and denominator by the highest degree of $x$ in the denominator, which is $x^2$ in this case:
$$\lim_{x\pm\infty}\frac{\frac{A}{x^2}}{1-\frac{2}{x}+\frac{1}{x^2}}=0$$
$$\frac{\lim_{x\pm\infty}\frac{A}{x^2}}{1-0+0}=\lim_{x\pm\infty}\frac{A}{x^2}=0$$
We know that as $A\in Z$, $\lim_{x\to\pm\infty}(A/x^2)=0$, so we can choose any positive number $(A\gt0)$ here. I would choose $A=2$.
So in conclusion, the function I come up with is $$f(x)=\frac{2}{(x-2)^2}$$.
The graph is shown below.