Limit of Composite Functions

Recently, a number of questions about the limit of composite functions have been discussed on the AP Calculus Community bulletin board and also on the AP Calc TEACHERS – AB/BC Facebook page. The theorem that we would like to apply in these cases is this: If f is continuous at b and , then .…

Infinite Musings

Students get confused about infinity, , because they think of it as a number, because used like a number. Even though they know there is no largest number, they think of infinity as the largest number. In studying limits, the starting point of calculus, infinite limits come up early on. We tell them . But…

L’Hospital’s Rule

Another application of the derivative L’Hospital’s Rule  Locally Linear L’Hospital’s Demonstration of the proof L’Hospital Rules the Graph Good Question An AP Exam question that can be used to delve deeper into L’Hospital’s Rule (2008 AB 6) Revised from a post of November 7, 2017 There will be two extra posts this week! Check tomorrow for some…

Continuity

Karl Weierstrass (1815 – 1897) was the mathematician who (finally) formalized the definition of continuity. Included in that definition was the epsilon-delta definition of limit. This definition has been pulled out, so to speak, and now is usually presented on its own. So, which came first – continuity or limit? The ideas and situations that…