Hello again, I cannot remember for the life of me how to do this sort of problem. I know that the answer is not zero or undefined though.

$\displaystyle lim x-> a (x^6-a^6)/(x^3-a^3) = $

(A) DNE

(B) 0

(C) $\displaystyle -1/(2a^3)$

(D) -1 / a^3

(E) $\displaystyle 1/(2a^3)$

All assistance is appreciated.