For (a), you want to take x< 0 (not

) and can assume that delta x is small enough that x+ delta x is also negative- then you can use "-x" as the formula for both g(x) and g(x+ delta x). If g(x)= -x, what is g(x+ delta x)?

Then take x> 0 and assume that delta x is small enough that x+ delta x is also positive- then you can use "

as the formula for both g(x) and g(x+ delta x). If

, what is g(x+ deltax)?

For (b), where x=0, taking the limit "from the left" means using g(0+ delta x)= -delta x and taking the limit "from the right" means using

.