I am trying to get the total differential for
y = x1x2/2x1 + x2
I have been given the answer
dy = [x2/2x1 + x2]dx1 - [2x1x2/(2x1+x2)^2]dx1 + [x1/2x1 + x2]dx2 - [x1x2/(2x1+x2)^2]dx2
Is this right?
It is my understanding that the general formula is F1dx1 + F2dx2, for y=F(x1,x2)
I don't understand why, in the second and fourth terms of the answer, the WHOLE of the denominator is being squared, rather than just the x1 or x2 that the partial derivative refers to......