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The solution of the differential equaton...

The solution of the differential equaton
`(dy)/(dx)=(x log x^(2)+x)/(sin y+ycos y)`, is

A

`ysiny=x^(2)logx+C`

B

`ysiny=x^(2)+C`

C

`ysiny=x^(2)+logx+C`

D

`y sin y=xlogx+C`

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The correct Answer is:
To solve the differential equation \[ \frac{dy}{dx} = \frac{x \log x^2 + x}{\sin y + y \cos y}, \] we will follow these steps: ### Step 1: Rearranging the Equation We start by multiplying both sides of the equation by \((\sin y + y \cos y)\): \[ (\sin y + y \cos y) \, dy = (x \log x^2 + x) \, dx. \] ### Step 2: Integrating Both Sides Next, we integrate both sides: \[ \int (\sin y + y \cos y) \, dy = \int (x \log x^2 + x) \, dx. \] ### Step 3: Integrating the Left Side For the left side, we can separate the integrals: \[ \int \sin y \, dy + \int y \cos y \, dy. \] The integral of \(\sin y\) is: \[ -\cos y. \] For \(\int y \cos y \, dy\), we can use integration by parts, where \(u = y\) and \(dv = \cos y \, dy\). Thus, \(du = dy\) and \(v = \sin y\): \[ \int y \cos y \, dy = y \sin y - \int \sin y \, dy = y \sin y + \cos y. \] Combining these results, we get: \[ \int (\sin y + y \cos y) \, dy = -\cos y + (y \sin y + \cos y) = y \sin y. \] ### Step 4: Integrating the Right Side Now, we integrate the right side: \[ \int (x \log x^2 + x) \, dx. \] We can simplify \(x \log x^2\) to \(2x \log x\). Thus, we need to compute: \[ \int (2x \log x + x) \, dx. \] Using integration by parts for \(\int 2x \log x \, dx\), let \(u = \log x\) and \(dv = 2x \, dx\). Then, \(du = \frac{1}{x} \, dx\) and \(v = x^2\): \[ \int 2x \log x \, dx = x^2 \log x - \int x^2 \cdot \frac{1}{x} \, dx = x^2 \log x - \int x \, dx = x^2 \log x - \frac{x^2}{2}. \] Now, integrating \(x\): \[ \int x \, dx = \frac{x^2}{2}. \] Combining these results, we have: \[ \int (2x \log x + x) \, dx = x^2 \log x - \frac{x^2}{2} + \frac{x^2}{2} = x^2 \log x. \] ### Step 5: Equating Both Integrals Now we equate the results from both sides: \[ y \sin y = x^2 \log x + C, \] where \(C\) is the constant of integration. ### Final Solution Thus, the solution to the differential equation is: \[ y \sin y = x^2 \log x + C. \] ---
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OBJECTIVE RD SHARMA ENGLISH-DIFFERENTIAL EQUATIONS-Chapter Test
  1. The general solution of the differential equation (dy)/(dx)+sin((x+y)/...

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  2. The solution of (dy)/(dx)-y=1, y(0)=1 is given by

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  3. The number of solution of y'=(x+1)/(x-1),y(1)=2, is

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  4. What is the solution of y'=1+x+y^(2)+xy^(2),y(0)=0?

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  5. Solution of the differential equation x(dy)/(dx)=y+sqrt(x^(2)+y^(2)), ...

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  6. Integral curve satisfying Y'=(x^2 +y^2)/(x^2-y^2) y' (1) ne 1 has th...

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  7. The differential equation which represents the family of plane curves ...

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  8. A continuously differentiable function y=f(x) , x in ((-pi)/(2) ,(pi)/...

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  9. The solution of the differential equation (d^(2)y)/(dx^(2))=e^(-2x), i...

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  10. The order and degree of the differential equation (d^(2)y)/(dx^(2))=sq...

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  11. The solution of differential equation (dy)/(dx)=y/x+(phi(y/x))/(phi'(y...

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  12. The solution of the equation log ((dy)/(dx))=a x+b y is (a) ( b ) (...

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  13. tan^(-1) x+tan^(-1)y=C is general solution of the differential equatio...

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  14. ydx-xdy+3x^(2)y^(2)e^(x^(3))dx=0

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  15. The solution of the differential equaton (dy)/(dx)=(x log x^(2)+x)/...

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  16. The solution of the differential equaiton cosxdy=y(sinx-y)dx ,0ltxlt...

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  17. The general solution of e^(x) cos ydx-e^(x) sin ydy=0 is

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  18. The solution of the differential equation (2y-1)dx-(2x+3)dy=0 is -

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  19. The solution of (dy)/(dx)+y=e^(-x), y(0)=0 " is"

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  20. The solution of the differential equation (dy)/(dx)=(x+y)/x satisfy...

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