Question

When can you use the substitution method for evaluating limits?

Answer 1

Only when the function is continuous.

Answer 2

umm.

Answer 3

What substitution method are you talking about?

Answer 4

so...would i be right to say. when you can plug in the x value and the denominator does not equal 0

Answer 5

Do you know what 'continuous' means?

Answer 6

yes...

Answer 7

Not really.

Answer 8

but am i right

Answer 9

No, you are not in certain cases. I saw a great example on Paul's Notes. Lemme bring it to ya.

Answer 10

http://www.calculus-help.com/how-do-you-evaluate-limits/

Answer 11

this is where i was supposed to get my answer but i don't really understand it so plz base it off of this

Answer 12

http://tutorial.math.lamar.edu/Classes/CalcI/TheLimit.aspx Look at the example 4 which tells you to not substitute always.

Answer 13

Use Paul's Math Notes(I recommend them to you personally).

Answer 14

please watch the video please help me

Answer 15

Hmm. I am very busy at the moment. I'd try to watch it later, but please have a look at Paul's Notes.

Answer 16

i don't get it

Answer 17

What don't you get?

Answer 18

why am i not right to say that you can use the substitution method when you plug in the x and the denominator odes not equal 0

Answer 19

There are exceptions, HorribleAtMath.
You need more and more practice to find out what they are.

And, it might mean that when the denominator is not equal to 0, then the function is continuous at that point.

Answer 20

if by substitution method you mean just plugging in the number, other causes of failure are getting a logarithm of zero, or a square root of a negative number at the point in question