Can you please help me with F(x) = ksqrt[x]-lnx ?

[IliveinUK]

For F(x) = k √(x) – ln x, find F' and F".

I basically have no clue how to solve the problem and I am completely lost. I do not know how to find the derivative without values for k, thus I have no clue on how to do the rest of the problems. I thank you for any help you can provide! =] i really appreciate it

 

[stapel]

The constant "k" is just some number. So differentiate the radical and the log in the usual manner, this time carrying a "k" along, instead of a "4" or a "-3/5". :wink:

Eliz.

 

[pka]

\(\displaystyle \L \begin{array}{l}
F(x) = k\sqrt x - \ln (x) \\
F'(x) = \frac{k}{{2\sqrt x }} - \frac{1}{x} \\
F''(x) = \frac{{ - k}}{{4\sqrt {x^3 } }} + \frac{1}{{x^2 }} \\
\end{array}\)

 

[stapel]

I do not know how to find the derivative without values for k....

I think you're making this way to complicated...? :shock:

You can find the derivative of g(x) = 2sqrt[x] - ln(x), h(x) = -4sqrt[x] - ln(x), j(x) = 12.3 sqrt[x] - ln(x), q(x) = -3/5 sqrt[x] - ln(x), right? So do the same thing here, but with "k" instead of "2", "-4", "12.3", or "-3/5". It's exactly the same process! :wink:

Eliz.