2006, Brian E. Blank, Steven George Krantz, “Applications of the Derivative”, in Calculus: Single Variable, Key College Publishing, →ISBN, section 6 (L’Hôpital’s Rule), page 303:
Many times a simple algebraic manipulation will put a limit into a form that we can study using l’Hôpital’s Rule.
2007, Adrian Banner, “L’Hôpital’s Rule and Overview of Limits”, in The Calculus Lifesaver: All the Tools You Need to Excel at Calculus, Princeton, N.J., Oxford: Princeton University Press, →ISBN, section 1 (L’Hôpital’s Rule), subsection 1 (Type A: 0/0 case), page 295:
Notice that if you put x = 3, then both top and bottom of the fraction are 0. This means we can use l’Hôpital’s Rule.
2017, Soo T. Tan, “Appendix B”, in Applied Calculus for the Managerial, Life, and Social Sciences, 10th edition, Cengage Learning, section 2 (The Indeterminate Forms 0/0 and ∞/∞ and l’Hôpital’s Rule), page 845:
To resolve a limit involving an indeterminate form, we sometimes need to apply l’Hôpital’s Rule more than once.
