MathsGee is Zero-Rated (You do not need data to access) on: Telkom |Dimension Data | Rain | MWEB

0 like 0 dislike
7 views
Evaluate this Limit Using Simplification

$$\lim _{x \rightarrow-2} \frac{3 x^{2}+x-10}{x+2}$$
| 7 views

0 like 0 dislike
Let us evaluate $\lim _{x_{x}-2} \frac{3 x^{2}+x-10}{x+2}$
1. Is the function $f(x)$ a polynomial function?
Answer: No, but the numerator and denominator separately are polynomials. They are combined into a single mathematical formula and so are now a closed-form function.
2. Is the value $x=a$ in the domain of $f(x)$ ?
Answer: No, since $\left(3(-2)^{2}+(-2)-10\right) /((-2)+2)$ is not defined.
Therefore, we consult the above Question/Answer discussion, and simplify the function, if we can.

$\frac{3 x^{2}+x-10}{x+2}=\frac{(x+2)(3 x-5)}{(x+2)}=3 x-5$
Since we are now left with a polynomial function that is defined when $x=-2$, we can now evaluate the limit by substitution:
$\operatorname{Lim}_{x_{\rightarrow}-2} \frac{3 x^{2}+x-10}{x+2}=\lim _{x_{\rightarrow}-2} 3 x-5=3(-2)-5=-11$
by Gold Status (10,269 points)

0 like 0 dislike