Help with a partial derivative question, thanks.

[kidzonety]

Use the table of values of f(x,y) to estimate the values of each of the following partial derivatives.


y=4.2 || 2.75262 ||| 0.27222 ||| 0.27107
y=4 ||| 5.74559 ||| 2.84839 ||| 0.64973
y=3.8 || 7.42708 ||| 5.84832 ||| 3.25237
||||||||| x=3.8 |||||| x=4 ||||||| x=4.2


fx(4.2 , 4) =
fxy(4 , 4) =

I know how to get fx, but don't know how to get fxy.
Hopefully you guys can teach me.
Thanks a lot!

 

[tiny-tim]

Welcome to PF!

Hi kidzonety! Welcome to PF!

(try using the X₂ tag just above the Reply box )

I know how to get fx, but don't know how to get fxy.

Do you know how to get f_xx?

If so, use f_xy = (f_x+y,x+y + f_x-y,x-y)/4