1. f(x) = 3/x^2 2. 1/(sqrt x)^3 - i don't know how to use limit. Please help me?
C Choi20 New member Joined Apr 29, 2013 Messages 3 Apr 29, 2013 #1 1. f(x) = 3/x^2 2. 1/(sqrt x)^3 - i don't know how to use limit. Please help me?
MarkFL Super Moderator Staff member Joined Nov 24, 2012 Messages 3,021 Apr 29, 2013 #2 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.) \(\displaystyle \displaystyle f'(x)=\lim_{h\to0}\frac{\dfrac{1}{(x+h)^{\frac{3}{2}}}-\dfrac{1}{x^{\frac{3}{2}}}}{h}\)
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.) \(\displaystyle \displaystyle f'(x)=\lim_{h\to0}\frac{\dfrac{1}{(x+h)^{\frac{3}{2}}}-\dfrac{1}{x^{\frac{3}{2}}}}{h}\)
D Deleted member 4993 Guest Apr 29, 2013 #3 Choi20 said: 1. f(x) = 3/x^2 2. 1/(sqrt x)^3 - i don't know how to use limit. Please help me? Click to expand... Well ... that would be the first thing you should learn. Open the text-book and start working with the example problems....
Choi20 said: 1. f(x) = 3/x^2 2. 1/(sqrt x)^3 - i don't know how to use limit. Please help me? Click to expand... Well ... that would be the first thing you should learn. Open the text-book and start working with the example problems....