# Partial derivative of second order from numerical values

• April 22nd 2010, 12:32 AM
mathieumg
Partial derivative of second order from numerical values
I am asked to estimate the value of $f_{xy}''(3;4)$ in

http://i43.tinypic.com/2gsh6wn.jpg

I have already found:

$f_x'(3;4) = -5$

$f_y'(3;4) = 2$

How do I find $f_{xy}''(3;4)$ from there?

Thanks a lot!
• April 22nd 2010, 03:11 AM
CaptainBlack
Quote:

Originally Posted by mathieumg
I am asked to estimate the value of $f_{xy}''(3;4)$ in

http://i43.tinypic.com/2gsh6wn.jpg

I have already found:

$f_x'(3;4) = -5$

$f_y'(3;4) = 2$

How do I find $f_{xy}''(3;4)$ from there?

Thanks a lot!

Estimate $f_y(2;4)$, $f_y(3,4)$ and $f_y(4;4)$ and use these to extimate $f_{yx}(3,4)$ or better yet look up even better methods in Abramowitz and Stegun

CB