How to find an explicit solution of the initial value problem x² dy/dx = y + xy, given y(1) = 1?

To solve the initial value problem defined by the equation x² dy/dx = y + xy with the initial condition y(1) = 1, we can start by rewriting the equation.

We can rearrange the equation to isolate  y/dx:

dy/dx = (y + xy) / x²

Next, we can separate the variables:

dy / (y + xy) = dx / x²

Now, let’s integrate both sides. We can simplify the left-hand side:

Factor out y from the denominator:

dy / (y(1 + x))

Now we integrate:

∫(1/y) dy = ∫(1/(1+x)) dx

These integrals lead to:

ln|y| = ln|1+x| + C

Exponentiating both sides gives us:

y = K(1+x)

where K = e^C is an arbitrary constant. Now, we apply the initial condition to find K.

Given that y(1) = 1:

1 = K(1+1)

1 = 2K

K = 1/2

Substituting K back into the equation for y:

y = (1/2)(1+x)

Thus, the explicit solution to the initial value problem is:

y = (1 + x) / 2

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