Find the partial derivatives of the function

[cwesto]

The problem:
f(x,y)=-\frac{-7x-2y}{9x+7y}

find:

f_x(x,y)
f_y(x,y)

The attempt:

f_x(x,y)=\frac{-7-2y}{9+7y}
f_y(x,y)=\frac{-7x-2}{9x+7}

Questions:

I'm not exactly sure how to find the partail derivative with a fraction like this one.

 

[Oerg]

use the quotient rule for differentiation? or product rule but with (9+7y)^(-1) for eg.

is this homework? it looks like the wrong forum to me

 

[cwesto]

Oh sorry.