I'm pretty bad at math, and Im doing some practice questions for school, I was wondering if someone could help me with this question, I cant get the right answer no matter what I try. Here's the question:
$ f(x) = \left\{\begin{array}{ll} -\frac{3}{x+3},&\text{if } x \lt -3;\\ 2x+9, &\text{if }x \gt -3. \end{array}\right.$
Calculate the following limits:
a) $\displaystyle \lim_{x\to -3^-} f(x)$
b) $\displaystyle \lim_{x\to -3} f(x)$
c) $\displaystyle \lim_{x\to -3^+} f(x)$
I've gotten (These are right)
B) DNE
C) 3
But I cant figure out A do I need the
$\frac{f(x + h) - f(x)}{h}$ or $\frac{f(x)-f(a)}{x-a}$ for that one? how would I work it out?
Here's my work if you want to look at what i did wrong: