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The Integrating Factor of the Differential Equation X D Y D X − Y = 2 X 2

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Question

The integrating factor of the differential equation \[x\frac{dy}{dx} - y = 2 x^2\]

Options

  • e−x

  • ey

  • \[\frac{1}{x}\]

  • x

MCQ
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Solution

\[\frac{1}{x}\]
 
We have,
\[x\frac{dy}{dx} - y = 2 x^2 \]
\[ \Rightarrow \frac{dy}{dx} - \frac{1}{x}y = 2x\]
\[\text{ Comparing with }\frac{dy}{dx} + Py = Q,\text{ we get }\]
\[P = - \frac{1}{x} \]
\[Q = 2x\]
Now,
\[I . F . = e^{- \int\frac{1}{x}dy} \]
\[ = e^{- \log\left| x \right|} \]
\[ = e^{log\left| \frac{1}{x} \right|} \]
\[ = \frac{1}{x}\]

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Chapter 21: Differential Equations - MCQ [Page 143]

APPEARS IN

R.D. Sharma Mathematics Volume 1 and 2 [English] Class 12
Chapter 21 Differential Equations
MCQ | Q 50 | Page 143

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