I don't know how to take out Δx when i do the question

If , show that

(by the first principles)

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- Aug 19th 2006, 03:09 AMling_c_0202derivative question, please help!
I don't know how to take out Δx when i do the question

If , show that

(by the first principles) - Aug 19th 2006, 06:41 AMtopsquarkQuote:

Originally Posted by**ling_c_0202**

Now, :

+ -

Now, and so:

.

-Dan - Aug 19th 2006, 07:43 AMCaptainBlackQuote:

Originally Posted by**topsquark**

to get the finite limit - maybe OK in Physics but not here :D

Quote:

Now, and so:

.

-Dan

- Aug 19th 2006, 12:55 PMtopsquarkQuote:

Originally Posted by**CaptainBlack**

-Dan - Aug 19th 2006, 06:05 PMThePerfectHacker
Let die Meister try.

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You need to find, for the point .

Recognize the famous limits,

Since,

(limit of constant function).

Therefore,

Because,*"if two limits of two functions exist at a point then the limit of their product exists at the point and is equal to the product of their limits"*.

Similary, since,

(limit of constant function).

Therefore,

Because,*"if two limits of two functions exist at a point then the limit of their products exists at the point and is equal to the product of their limits"*

Thus,

=

Because,*"if the limits of two functions exist at a point then the limit of the sum of these functions exists at the point and is equal to the sum of the limits"*. - Aug 24th 2006, 03:55 AMling_c_0202thank you
Oh... I 've got it!! Thanks a lot!