All!

Please, how do I get f'(x) and f''(x) if I have f(x)=x/(x^lnx)?

Many thanks!

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- Jan 22nd 2013, 03:21 AMBoox/x^2lnx
All!

Please, how do I get f'(x) and f''(x) if I have f(x)=x/(x^lnx)?

Many thanks! - Jan 22nd 2013, 05:49 AMtopsquarkRe: x/x^2lnx
- Jan 22nd 2013, 06:16 AMSorobanRe: x/x^2lnx
Hello, Boo!

Quote:

You need Logarithmic Differentiation.

We have: .

Take logs: .

. . . . . . . .

. . . . . . . .

. . . . . . . .

Differentiate implicitly:

. . . . . . . .

. . . . . . . .

. . . . . . . .

. . . . . . . .

Hence: . .

Now repeat the process to find the second derivative,