Limits of composite functions | Limits and continuity | AP Calculus AB | Khan Academy

Sal solves a few examples where the graphs of two functions are given and we're asked to find the limit of a function that is a composition of the two functions.

AP Calculus AB on Khan Academy: Bill Scott uses Khan Academy to teach AP Calculus at Phillips Academy in Andover, Massachusetts, and heÕs part of the teaching team that helped develop Khan AcademyÕs AP lessons. Phillips Academy was one of the first schools to teach AP nearly 60 years ago.

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[mychaelsmith]

In the first problem, g only preserves the limit if it is continuous, so you can't always do that.

[arielfuxman]

In the last example, should not it be +infinity?

[neelchopra]

last one is positive infinity, correct?

[steadgotthetime]

Please note Sal did the last problem wrong, the answer is positive infinity

[AbrahamYohannes-moxj]

It has a problem in the answer of the last question

[tanbeerkaur]

how do you make this video and record voice at same time

[patlerds]

I think this entire video is incorrect. Not with the answers but the problems. Instead of plugging the limit into the outer function and solving for h(limit) for example, shouldn't you do the limit of the outside function as well?

[Lsr]

i don't really understand the last example, how the x is approaching 1 ?? the graph is coming down not a straight line from the left