using the first principle of differentiation, find the first derivatives of

Choi20

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Apr 29, 2013
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1. f(x) = 3/x^2

2.
1/(sqrt x)^3

- i don't know how to use limit. Please help me?
 
Typically differentiating by first principles involves evaluating the limit:

\(\displaystyle \displaystyle f'(x)\equiv\lim_{h\to0}\frac{f(x+h)-f(x)}{h}\)

and then one seeks algebraically for a way to divide out the \(\displaystyle h\) in the denominator.

I'll set the limits up and leave you to to algebra, and please feel free to post your work if you get stuck.

1.) \(\displaystyle \displaystyle f'(x)=3\lim_{h\to0}\frac{\dfrac{1}{(x+h)^2}-\dfrac{1}{x^2}}{h}\)

2.) \(\displaystyle \displaystyle f'(x)=\lim_{h\to0}\frac{\dfrac{1}{(x+h)^{\frac{3}{2}}}-\dfrac{1}{x^{\frac{3}{2}}}}{h}\)
 
1. f(x) = 3/x^2

2.
1/(sqrt x)^3

- i don't know how to use
limit. Please help me?

Well ... that would be the first thing you should learn.

Open the text-book and start working with the example problems....
 
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