+2 votes
in General by kratos

For the differential equation, find the particular solution (x y2x) dx (y + x2y) dy = 0when x = 2, y = 0

1 Answer

+1 vote
by kratos
 
Best answer

(x y2x) dx (y + x2y) dy = 0

x(1 y2) dx = y(1 + x2) dy

$(x"d"x)/(1 + x^2) = (y"d"y)/(1 - y^2)$

Integrating on both sides, we get

$int (x)/(1 + x^2) "d"x = int (y)/(1 - y^2) "d"y$

$int (2x)/(1 + x^2) "d"x = - int (-2y)/(1 - y^2) "d"y$

log |1 + x2| = log |1 y2| + log |c|

log |1 + x2| = $log|"c"/(1 - y^2)|$

1 + x2 = $"c"/(1 - y^2)$

(1 + x2)(1 y2) = c ......(i)

When x = 2, y = 0, we have

(1 + 4)(1 0) = c

c = 5

Substituting c = 5 in (i), we get

(1 + x2)(1 y2) = 5, which is the required particular solution.

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