We have indeterminateness of type
0/0,
i.e. limit for the numerator is
$$\lim_{x \to 0^+} \log{\left(1 - x^{2} \right)} = 0$$
and limit for the denominator is
$$\lim_{x \to 0^+} x^{2} = 0$$
Let's take derivatives of the numerator and denominator until we eliminate indeterninateness.
$$\lim_{x \to 0^+}\left(\frac{\log{\left(1 - x^{2} \right)}}{x^{2}}\right)$$
=
Let's transform the function under the limit a few
$$\lim_{x \to 0^+}\left(\frac{\log{\left(1 - x^{2} \right)}}{x^{2}}\right)$$
=
$$\lim_{x \to 0^+}\left(\frac{\frac{d}{d x} \log{\left(1 - x^{2} \right)}}{\frac{d}{d x} x^{2}}\right)$$
=
$$\lim_{x \to 0^+}\left(- \frac{1}{1 - x^{2}}\right)$$
=
$$\lim_{x \to 0^+} -1$$
=
$$\lim_{x \to 0^+}\left(\frac{\frac{d}{d x} \left(- 2 x\right)}{\frac{d}{d x} 2 x}\right)$$
=
$$\lim_{x \to 0^+} -1$$
=
$$\lim_{x \to 0^+} -1$$
=
$$-1$$
It can be seen that we have applied Lopital's rule (we have taken derivatives with respect to the numerator and denominator) 2 time(s)