Can you help me with the steps getting to the right side from the left of the equation.

Can you help me with the steps getting to the right side from the left of the equation.

f[x_] = (1 - 3^(1/x))/(1 + 3^(1/x));
Plot[f[x], {x, -1, 1}, Exclusions -> {x == 0}]

From the documentation for Limit,
Direction -> -1takes variables to approach their limits by decreasing from larger values.
Limit[f[x], x -> 0, Direction -> -1]
-1
Using WolframAlpha from within Mathematica,
WolframAlpha["Limit[(1-3^(1/x))/(1+3^(1/x)), x -> 0, Direction -> -1]",
{{"Limit", 2}, "Content"}, PodStates -> {"Limit__Step-by-step solution"}]
