l'hopital rule

Indeterminate forms occur in the evaluation of limits when direct substitution does not produce a definite value. We have: \[
\frac{0}{0}
\qquad
\frac{\infty}{\infty}
\qquad
0 \cdot \infty
\qquad
\infty – \infty
\]

\[
1^{\infty}
\qquad
0^{0}
\qquad
\infty^{0}
\]