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Question
The differential equation `y dy/dx + x = 0` represents family of ______.
Options
circles
parabolas
ellipses
hyperbolas
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Solution
The differential equation `y dy/dx + x = 0` represents family of circles.
Explanation:
`y dy/dx + x = 0`
∴ `int y dy + int x dx = C`
∴ `y^2/2 +x^2/2 = C`
∴ x2 + y2 = 2C, which is a circle.
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