CBSE Class 12 Math 2012 Solved Paper

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Question : 12 of 29
 
Marks: +1, -0
Solve the following differential equation:
2x2dxdy - 2xy + y2 = 0
Solution:
Here,
2x2dxdy - 2xy + y2 = 0
dydx = 2xy−y22x2
Hence the given equation is an homogeneous equation.
Let y = vx
and dydx = y + x dvdx
So, v + x dvdx
So, v + x dvdx = 2x(vx)−(vx)22x2
= 2v−v22 = v−v22
⇒ x dvdx = - v22
⇒ 2 ∫ 1v2 dv = ∫ −∫dxx
⇒ 2 (−1v) = - log |x| + c
⇒ 2xy = log |x| + c
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