Solving limits with substitution (KristaKingMath)

► My Limits & Continuity course: www.kristakingmath.com/limits...
Substitution is the easiest way to evaluate a limit, but it's also the most limited. With substitution, you simply take the value that the limit approaches, and plug it into the function. If you can get a real number answer doing this, then you've found the value of the limit, and there's nothing else you need to do.
But most limits can't be evaluated this way. If you try substitution, often you'll end up with an indeterminate form, like 0/0. When this is the case, you'll need to use a more advanced technique, like factoring, conjugate method, or L'Hospital's rule to evaluate the limit.
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[@jeremymcdonald5281]

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[@hoomaneshghi253]

there are some cases that if we plug in the value of x in the function we get out a value of the function but that is not the value of limit
so it is not generally true that if we plug in the output will be the limit
like floor functions and ...

[@octalitic]

Great work! Thanks. :-)

[@kristakingmath]

+nanofloyd You're welcome!

[@tinay_reads]

What if I have a real number answer but it is far from the value of the approaching number? Is it gonna be undefined or is it the final answer still?

[@philippelorge1451]

It would be undefined, because a^2 + b^2 =C^2