Question:
Evaluate
$\lim _{x \rightarrow-2}\left(\frac{x^{3}+8}{x+2}\right)$
Solution:
To evaluate: $\lim _{x \rightarrow-2} \frac{x^{3}+8}{x+2}$
Formula used:
We have,
$\lim _{x \rightarrow a} f(x)=f(a)$ and
$x^{3}+y^{3}=(x+y)\left(x^{2}-x y+y^{2}\right)$
As $x \rightarrow-2$, we have
$\lim _{x \rightarrow-2} \frac{x^{3}+8}{x+2}=\lim _{x \rightarrow-2} \frac{(x+2)\left(x^{2}-2 x+4\right)}{x+2}$
$\lim _{x \rightarrow-2} \frac{x^{3}+8}{x+2}=\lim _{x \rightarrow-2}\left(x^{2}-2 x+4\right)$
$\lim _{x \rightarrow-2} \frac{x^{3}+8}{x+2}=4-4+4$
$\lim _{x \rightarrow-2} \frac{x^{3}+8}{x+2}=4$
Thus, the value of $\lim _{x \rightarrow-2} \frac{x^{3}+8}{x+2}$ is 4