Hello community members
I have been trying to understand differentials and came across this notes which explains inexact differentials. BUt having trouble grasping it. Could someone help me understand these 2 questions?
1)Here, Equation 145 is given to be a gradient giving a direction in x-y plane.But I think the equation just gives a slope as it does not appear to be a vector.
2)Here in equation 147
how is
$$Y′∂σ/∂x=X′∂σ/∂y=X′Y′/τ$$
ie how did they arrive at $$X′Y′/τ$$
Would be really grateful if someone could help me figure this out, please.
Thank you.