Solve the diff eqn dy/y + dx/x =0
Let's rearrange by shifting x components to right hand side
dy / y = - dx /x. ( variable seperable eqn )
Integrating both sides
∫ 1/y dy = - ∫ 1/x dx
= log | y | = - log | x | + log c ( we can multiply constant c with log )
= log | y | = log c - log | x |
= log | y | = log ( c / x ). ( we can remove log on both sides
= y = c / x or ( y • x ) = c and it is the solution