1.

The solution of the differential equation `(dy)/(dx) = 1/(xy[x^(2)siny^(2)+1])` isA. `x^(2)(cosy^(2)-siny^(2)-2Ce^(-y^(2)))=2`B. `y^(2)(cosx^(2)-siny^(2)-2Ce^(-y^(2)))=4C`C. None of theseD. a system of circles

Answer» Correct Answer - A
`(dy)/(dx) = 1/(xy[x^(2)siny^(2)+1])`
or `1/x^(3)(dx)/(dy) -1/x^(2)y=ysiny^(2)`
Putting `-1//x^(2)=u`, we get
`(du)/(dy)+2uy=2ysiny^(2)`.
I.F. `=e^(y^(2))`
Thus, solution is `ue^(y^(3))=int2ysiny^(2)e^(y^(2))dy+C`
`=int(sint)e^(t)dt+C`
`=1/2e^(y^(3))(siny^(2)-cosy^(2))+c`
or `2u=(siny^(2)-cosy^(2))+2Ce^(-y^(2))`
or `2=x^(2)[cosy^(2)-siny^(2)-2Ce^(-y^(2))]`


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