Hello! There is an equation. If I take the partial derivative from it, the part with ∂ appears in the output. This part should be automatically equal to 0. How can I fix this?
Ek = (m1*Dt[y, t]*Dt[y, t])/2 + (m2*(l*Dt[\[Phi], t]*Sin[\[Phi]])^2)/
2 + (m2*(l*Dt[\[Phi], t]*Cos[\[Phi]] + Dt[y, t])^2)/2
Thank you in advance!
When you take partial derivatives with respect to y,\[Phi], these must be independent variables, not themselves functions (of what? of themselves?).