General solution of differential equation ylog⁡ydx−xdy=0y \log y dx - x dy = 0 is :

Answer: x=Alog⁡yx = A \log y

Step-by-step solution

Step 1: Separate the variables

The given differential equation is ylog⁡ydx−xdy=0y \log y dx - x dy = 0. To solve this, we first rearrange the terms to separate the variables xx and yy. We move the xdyx dy term to the right side and then divide both sides by xx and ylog⁡yy \log y to group dxdx with xx and dydy with yy.

Step 2: Integrate both sides

Now that the variables are separated, we integrate both sides of the equation. The left side is a standard integral of 1/x1/x, and the right side requires a substitution to solve.

Step 3: Solve the integrals

For the left side, ∫1xdx=log⁡∣x∣\int \frac{1}{x} dx = \log |x|. For the right side, let u=log⁡yu = \log y. Then du=1ydydu = \frac{1}{y} dy. So, ∫1ylog⁡ydy=∫1udu=log⁡∣u∣=log⁡∣log⁡y∣\int \frac{1}{y \log y} dy = \int \frac{1}{u} du = \log |u| = \log |\log y|. We add the constant of integration CC to one side.

Step 4: Simplify the general solution

We can combine the logarithmic terms on the left side using the property log⁡a−log⁡b=log⁡(a/b)\log a - \log b = \log (a/b). Then, we convert the logarithmic equation to an exponential form. Let eC=Ae^C = A, where AA is an arbitrary positive constant. This gives us the general solution.

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