Tenemos la indeterminación de tipo
0/0,
tal que el límite para el numerador es
$$\lim_{x \to 0^+}\left(- \sqrt{1 - x} + \sqrt{x + 1}\right) = 0$$
y el límite para el denominador es
$$\lim_{x \to 0^+} x^{\frac{7}{2}} = 0$$
Vamos a probar las derivadas del numerador y denominador hasta eliminar la indeterminación.
$$\lim_{x \to 0^+}\left(\frac{- \sqrt{1 - x} + \sqrt{x + 1}}{x^{\frac{7}{2}}}\right)$$
=
$$\lim_{x \to 0^+}\left(\frac{\frac{d}{d x} \left(- \sqrt{1 - x} + \sqrt{x + 1}\right)}{\frac{d}{d x} x^{\frac{7}{2}}}\right)$$
=
$$\lim_{x \to 0^+}\left(\frac{2 \left(\frac{1}{2 \sqrt{x + 1}} + \frac{1}{2 \sqrt{1 - x}}\right)}{7 x^{\frac{5}{2}}}\right)$$
=
$$\lim_{x \to 0^+}\left(\frac{\frac{d}{d x} \left(\frac{1}{2 \sqrt{x + 1}} + \frac{1}{2 \sqrt{1 - x}}\right)}{\frac{d}{d x} \frac{7 x^{\frac{5}{2}}}{2}}\right)$$
=
$$\lim_{x \to 0^+}\left(\frac{4 \left(- \frac{1}{4 \left(x \sqrt{x + 1} + \sqrt{x + 1}\right)} + \frac{1}{4 \left(- x \sqrt{1 - x} + \sqrt{1 - x}\right)}\right)}{35 x^{\frac{3}{2}}}\right)$$
=
$$\lim_{x \to 0^+}\left(\frac{\frac{d}{d x} \left(- \frac{1}{4 \left(x \sqrt{x + 1} + \sqrt{x + 1}\right)} + \frac{1}{4 \left(- x \sqrt{1 - x} + \sqrt{1 - x}\right)}\right)}{\frac{d}{d x} \frac{35 x^{\frac{3}{2}}}{4}}\right)$$
=
$$\lim_{x \to 0^+}\left(\frac{8 \left(\frac{x}{8 x^{3} \sqrt{x + 1} + 24 x^{2} \sqrt{x + 1} + 24 x \sqrt{x + 1} + 8 \sqrt{x + 1}} - \frac{x}{- 8 x^{3} \sqrt{1 - x} + 24 x^{2} \sqrt{1 - x} - 24 x \sqrt{1 - x} + 8 \sqrt{1 - x}} + \frac{\sqrt{1 - x}}{4 \left(- x^{3} + 3 x^{2} - 3 x + 1\right)} + \frac{\sqrt{x + 1}}{4 \left(x^{3} + 3 x^{2} + 3 x + 1\right)} + \frac{1}{8 x^{3} \sqrt{x + 1} + 24 x^{2} \sqrt{x + 1} + 24 x \sqrt{x + 1} + 8 \sqrt{x + 1}} + \frac{1}{- 8 x^{3} \sqrt{1 - x} + 24 x^{2} \sqrt{1 - x} - 24 x \sqrt{1 - x} + 8 \sqrt{1 - x}}\right)}{105 \sqrt{x}}\right)$$
=
$$\lim_{x \to 0^+}\left(\frac{\frac{d}{d x} \left(\frac{x}{8 x^{3} \sqrt{x + 1} + 24 x^{2} \sqrt{x + 1} + 24 x \sqrt{x + 1} + 8 \sqrt{x + 1}} - \frac{x}{- 8 x^{3} \sqrt{1 - x} + 24 x^{2} \sqrt{1 - x} - 24 x \sqrt{1 - x} + 8 \sqrt{1 - x}} + \frac{\sqrt{1 - x}}{4 \left(- x^{3} + 3 x^{2} - 3 x + 1\right)} + \frac{\sqrt{x + 1}}{4 \left(x^{3} + 3 x^{2} + 3 x + 1\right)} + \frac{1}{8 x^{3} \sqrt{x + 1} + 24 x^{2} \sqrt{x + 1} + 24 x \sqrt{x + 1} + 8 \sqrt{x + 1}} + \frac{1}{- 8 x^{3} \sqrt{1 - x} + 24 x^{2} \sqrt{1 - x} - 24 x \sqrt{1 - x} + 8 \sqrt{1 - x}}\right)}{\frac{d}{d x} \frac{105 \sqrt{x}}{8}}\right)$$
=
$$\lim_{x \to 0^+}\left(\frac{16 \sqrt{x} \left(\frac{x \left(- \frac{4 x^{3}}{\sqrt{x + 1}} - 24 x^{2} \sqrt{x + 1} - \frac{12 x^{2}}{\sqrt{x + 1}} - 48 x \sqrt{x + 1} - \frac{12 x}{\sqrt{x + 1}} - 24 \sqrt{x + 1} - \frac{4}{\sqrt{x + 1}}\right)}{\left(8 x^{3} \sqrt{x + 1} + 24 x^{2} \sqrt{x + 1} + 24 x \sqrt{x + 1} + 8 \sqrt{x + 1}\right)^{2}} - \frac{x \left(- \frac{4 x^{3}}{\sqrt{1 - x}} + 24 x^{2} \sqrt{1 - x} + \frac{12 x^{2}}{\sqrt{1 - x}} - 48 x \sqrt{1 - x} - \frac{12 x}{\sqrt{1 - x}} + 24 \sqrt{1 - x} + \frac{4}{\sqrt{1 - x}}\right)}{\left(- 8 x^{3} \sqrt{1 - x} + 24 x^{2} \sqrt{1 - x} - 24 x \sqrt{1 - x} + 8 \sqrt{1 - x}\right)^{2}} + \frac{\sqrt{1 - x} \left(3 x^{2} - 6 x + 3\right)}{4 \left(- x^{3} + 3 x^{2} - 3 x + 1\right)^{2}} + \frac{\sqrt{x + 1} \left(- 3 x^{2} - 6 x - 3\right)}{4 \left(x^{3} + 3 x^{2} + 3 x + 1\right)^{2}} + \frac{1}{8 x^{3} \sqrt{x + 1} + 24 x^{2} \sqrt{x + 1} + 24 x \sqrt{x + 1} + 8 \sqrt{x + 1}} + \frac{- \frac{4 x^{3}}{\sqrt{x + 1}} - 24 x^{2} \sqrt{x + 1} - \frac{12 x^{2}}{\sqrt{x + 1}} - 48 x \sqrt{x + 1} - \frac{12 x}{\sqrt{x + 1}} - 24 \sqrt{x + 1} - \frac{4}{\sqrt{x + 1}}}{\left(8 x^{3} \sqrt{x + 1} + 24 x^{2} \sqrt{x + 1} + 24 x \sqrt{x + 1} + 8 \sqrt{x + 1}\right)^{2}} - \frac{1}{- 8 x^{3} \sqrt{1 - x} + 24 x^{2} \sqrt{1 - x} - 24 x \sqrt{1 - x} + 8 \sqrt{1 - x}} + \frac{- \frac{4 x^{3}}{\sqrt{1 - x}} + 24 x^{2} \sqrt{1 - x} + \frac{12 x^{2}}{\sqrt{1 - x}} - 48 x \sqrt{1 - x} - \frac{12 x}{\sqrt{1 - x}} + 24 \sqrt{1 - x} + \frac{4}{\sqrt{1 - x}}}{\left(- 8 x^{3} \sqrt{1 - x} + 24 x^{2} \sqrt{1 - x} - 24 x \sqrt{1 - x} + 8 \sqrt{1 - x}\right)^{2}} + \frac{1}{8 \sqrt{x + 1} \left(x^{3} + 3 x^{2} + 3 x + 1\right)} - \frac{1}{8 \sqrt{1 - x} \left(- x^{3} + 3 x^{2} - 3 x + 1\right)}\right)}{105}\right)$$
=
$$\lim_{x \to 0^+}\left(\frac{16 \sqrt{x} \left(\frac{x \left(- \frac{4 x^{3}}{\sqrt{x + 1}} - 24 x^{2} \sqrt{x + 1} - \frac{12 x^{2}}{\sqrt{x + 1}} - 48 x \sqrt{x + 1} - \frac{12 x}{\sqrt{x + 1}} - 24 \sqrt{x + 1} - \frac{4}{\sqrt{x + 1}}\right)}{\left(8 x^{3} \sqrt{x + 1} + 24 x^{2} \sqrt{x + 1} + 24 x \sqrt{x + 1} + 8 \sqrt{x + 1}\right)^{2}} - \frac{x \left(- \frac{4 x^{3}}{\sqrt{1 - x}} + 24 x^{2} \sqrt{1 - x} + \frac{12 x^{2}}{\sqrt{1 - x}} - 48 x \sqrt{1 - x} - \frac{12 x}{\sqrt{1 - x}} + 24 \sqrt{1 - x} + \frac{4}{\sqrt{1 - x}}\right)}{\left(- 8 x^{3} \sqrt{1 - x} + 24 x^{2} \sqrt{1 - x} - 24 x \sqrt{1 - x} + 8 \sqrt{1 - x}\right)^{2}} + \frac{\sqrt{1 - x} \left(3 x^{2} - 6 x + 3\right)}{4 \left(- x^{3} + 3 x^{2} - 3 x + 1\right)^{2}} + \frac{\sqrt{x + 1} \left(- 3 x^{2} - 6 x - 3\right)}{4 \left(x^{3} + 3 x^{2} + 3 x + 1\right)^{2}} + \frac{1}{8 x^{3} \sqrt{x + 1} + 24 x^{2} \sqrt{x + 1} + 24 x \sqrt{x + 1} + 8 \sqrt{x + 1}} + \frac{- \frac{4 x^{3}}{\sqrt{x + 1}} - 24 x^{2} \sqrt{x + 1} - \frac{12 x^{2}}{\sqrt{x + 1}} - 48 x \sqrt{x + 1} - \frac{12 x}{\sqrt{x + 1}} - 24 \sqrt{x + 1} - \frac{4}{\sqrt{x + 1}}}{\left(8 x^{3} \sqrt{x + 1} + 24 x^{2} \sqrt{x + 1} + 24 x \sqrt{x + 1} + 8 \sqrt{x + 1}\right)^{2}} - \frac{1}{- 8 x^{3} \sqrt{1 - x} + 24 x^{2} \sqrt{1 - x} - 24 x \sqrt{1 - x} + 8 \sqrt{1 - x}} + \frac{- \frac{4 x^{3}}{\sqrt{1 - x}} + 24 x^{2} \sqrt{1 - x} + \frac{12 x^{2}}{\sqrt{1 - x}} - 48 x \sqrt{1 - x} - \frac{12 x}{\sqrt{1 - x}} + 24 \sqrt{1 - x} + \frac{4}{\sqrt{1 - x}}}{\left(- 8 x^{3} \sqrt{1 - x} + 24 x^{2} \sqrt{1 - x} - 24 x \sqrt{1 - x} + 8 \sqrt{1 - x}\right)^{2}} + \frac{1}{8 \sqrt{x + 1} \left(x^{3} + 3 x^{2} + 3 x + 1\right)} - \frac{1}{8 \sqrt{1 - x} \left(- x^{3} + 3 x^{2} - 3 x + 1\right)}\right)}{105}\right)$$
=
$$\infty$$
Como puedes ver, hemos aplicado el método de l'Hopital (utilizando la derivada del numerador y denominador) 4 vez (veces)