Form the differential equation of the family of ellipses having foci on y-axis and centre at origin.

Explanation

To form the differential equation of the family of ellipses with foci on the y-axis and the center at the origin, we will follow these steps:

### Step 1: Write the equation of the ellipse
The general equation of an ellipse with foci on the y-axis and center at the origin is given by:

\[ \frac{x^2}{b^2} + \frac{y^2}{a^2} = 1 \]
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