I have come across several questions along the lines of "How do I complete this derivation?" where the answer sometimes is just mathematical, but generally they need some sort of physical insight to go from the original equation to the final one where the authors of the book/paper/etc pull the classic "And so it's obvious that..."
For a more recent example, Solving the Tolman–Oppenheimer–Volkoff (TOV) equation
while vertical wind gradients in the atmospheric boundary layer is actually an example that probably should be OT since it's purely a math question and no extra physical insight was needed... but I was feeling friendly.
So do we tag these as homework? And more importantly, do we treat them as such and not provide the solution while also expecting the OP to include their work so far and where specifically he/she is stuck?