## University Calculus: Early Transcendentals (3rd Edition)

$$\lim_{x\to0^+}\frac{1}{3x}=\infty$$
$$A=\lim_{x\to0^+}\frac{1}{3x}$$ As $x\to0^+$, $3x$ approaches $0$ from the right, so $1/3x$ will approach $\infty$. Therefore, $$A=\lim_{x\to0^+}\frac{1}{3x}=\infty$$