If lim [x^4-1/x-1] (x ∈ 1) = lim [x^3-a^3/x-a] (x ∈ a) find all possible values of a.

Question

If \(\lim\limits_{x\longrightarrow1}[\frac{x^4-1}{x-1}] \)= \(\lim\limits_{x\longrightarrow\,a}[\frac{x^3-a^3}{x-a}] \), find all possible values of a.

lim [x⁴-1/x-1] (x ∈ 1) = lim [x³-a³/x-a] (x ∈ a) 

Answer 1

\(\lim\limits_{x\longrightarrow1}[\frac{x^4-1}{x-1}] \)= \(\lim\limits_{x\longrightarrow\,a}[\frac{x^3-a^3}{x-a}] \)