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(a) Show that the given equation is homogeneous.
dy/dx = x²+xy+y²/x²

User Syntagma
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Final answer:

The provided differential equation is shown to be homogeneous, and it is demonstrated that the distance of any point P to the origin is invariant under rotations of the coordinate system.

Step-by-step explanation:

Show that the Equation is Homogeneous

To prove that the differential equation dy/dx = (x² + xy + y²) / x² is homogeneous, we can express each term as a function of one variable by dividing through by x². This yields:

dy/dx = 1 + (y/x) + (y/x)²

Notice that each term is now a function of the variable (y/x), which means that the degree of each term equals the degree of x, verifying the equation as homogeneous.

Distance Invariance Under Rotation

To show that the distance of a point P to the origin is invariant under rotations of the coordinate system, consider a point P with coordinates (x, y) in the original system. After rotation, the coordinates may change to (x', y'), but the squared distance from P to the origin, which is x² + y², remains the same because it only involves the sum of the squares of the coordinates, which is unchanged by rotation. Hence, the distance remains invariant as:

x² + y² = x'² + y'²

User Siva Gnanam
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