Here's the question you clicked on:
nickymarden
Given the function... is it derivable at the point P(0,-1) ?
use the definition: the function is derivable at x=0 if \[ \large \lim_{x\to0}\frac{f(x)-f(0)}{x-0}=\lim_{x\to0}\frac{f(x)+1}{x} \]
this limit has to exist. so u now turn to one-sided limits.
Oh yeeah, thank you so much. After you use the rules you forget the definition.
actually it is easier than that, although of course @helder_edwin is correct
just take the derivative of each piece, and replace \(x\) by \(0\) if you get the same answer, then yes, if you get a different answer, then no
you can pretty much do it with your eyeballs first one is 3 second one is \(10x+3\)and when you replace \(x\) by 0 in both you get 3
haha thanks :) Not everyone can do it with their eyeballs ;)