Question #f5f35

1 Answer
Feb 8, 2018

# GS : y=2+ce^{x/6(6+3x-2x^2)}#.

Explanation:

Let us observe that, the given diff. eqn. is,

#dy=(2x^2+y-x^2y+xy-2x-2)dx#

#={(2x^2-2x-2)-(x^2-x-1)y}dx#,

#={2(x^2-x-1)-(x^2-x-1)y}dx#,

#=(x^2-x-1)(2-y)dx#.

#rArr dy/(2-y)=(x^2-x-1)dx, or, #

# dy/(y-2)+(x^2-x-1)dx=0#.

Obviously, it is a separable variable type diff. eqn., and, now,

when the variables are separated, integrating it term by term,

we get its general solution (GS) as shown below :

#intdy/(y-2)+int(x^2-x-1)dx=lnc#.

#:. ln(y-2)+(x^3/3-x^2/2-x)=lnc#.

#:. ln(y-2)+x/6(2x^2-3x-6)=lnc#.

#:. ln((y-2)/c)=x/6(6+3x-2x^2)#.

#:. (y-2)/c=e^{x/6(6+3x-2x^2)}#.

#rArr y=2+ce^{x/6(6+3x-2x^2)},# is the desired GS.

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