# Math Help - Economics differentiation question

1. ## Economics differentiation question

Can somebody walk me through this answer

I have these:

$w = ∂F(K, AL) / ∂L$ and $r = ∂F(K, AL) / ∂K$.

Where $K = K/AL$

I have the answer $A[ f (k) - kf '(k)]$ but confused on the steps to prove it

Thanks

2. ## Re: Economics differentiation question

define all terms and tell us what the question wants you to do first !

3. ## Re: Economics differentiation question

$A = Technology$
$l = Labour$
$K = Capital$

$w = Marginal product of labour$
$R = Marginal product of capital$

I've got to show the MPL is the function provided above (the answer)