## Calculus: Early Transcendentals (2nd Edition)

$\displaystyle \lim_{x\rightarrow 3^{-}}f(x)=4,\quad\lim_{x\rightarrow 3^{+}}f(x)=5$
As x approaches 3 from the left, $f(x)=4$, a constant function, so $\displaystyle \lim_{x\rightarrow 3^{-}}f(x)=4$ As x approaches 3 from the right, $f(x)=x+2$, a linear function, so $\displaystyle \lim_{x\rightarrow 3^{+}}f(x)=3+2=5$