use the chain rule to find the indicated partial derivatives

题目

use the chain rule to find the indicated partial derivatives
N=(p+q)/(p+r),p=u+vw q=v+uw r=w+uv ;
partial N/partial u ,partial N/partial v ,partial N/ partial w ,when u=2 ,v=3 ,w=4

答案

when u=2 ,v=3 ,w=4 then p=14 q=11 r=10∵∂N/∂p=1/(p+r)-(p+q)/(p+r)^2,∂N/∂q=1/(p+r),∂N/∂r=-(p+q)/(p+r)^2∂p/∂u=1 ∂q/∂u=w ∂r/∂u=v...