Question

Solve : $(e^3+1)\cos xdx+e^y\sin xdy=0$

Answer 1

$(e^3+1)cosxdx=-e^{y}sinxdy(e^3+1)\int \left(\frac{cosx}{sinx}dx\right)=-\int e^{y}dy(e^3+1)log\left|sinx\right|=-e^y+c$