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Which of the following is a homogenous differential equation ?A. `(4x+6y+5)dy-(3y+2x+4)dx=0`B. `(xy)dx-(x^(3)+y^(3))dy=0`C. `(x^(3)+2y^(2))dx+2xydy=0`D. `y^(2)dx+(x^(2)-xy-y^(2))dy=0`

Answer» `(a)` Given equation `(4x+6y+5)dy-(3y+2x+4)dx=0` can be written as
`(dy)/(dx)=(3y+2x+4)/(4x+6y+5)implies(dy)/(dx)=(x(3*(y)/(x)+2+(4)/(x))/(x(4+6(y)/(x)+(5)/(x))`
whichis non-homogenous differential equation.
`(b)` Given differential equation
`xydx-(x^(3)+y^(3))dy=0`
from the separating of variables,
`(x^(3)+y^(3))dy=xydximplies(dy)/(dx)=(xy)/(x^(3)+y^(3))`
`implies (dy)/(dx)=((y)/(x^(2)))/(1+((y)/(x))^(3))`
which is non-homogenous differential equation
`(c )` Given differential eqaution
`(x^(3)+2y^(2))dx+2 xy dy=0`
`2xy dy=-(x^(3)+2y^(2))dx`
From the separating of variables,
`(dy)/(dx)=-(x^(3)+2y^(2))/(2xy)implies(dy)/(dx)=(1+(2y^(2))/(x^(3)))/((2y)/(x^(2)))`
which is non-homogenous differential equation.
`(d)` Given differential equation
`y^(2)dx+(x^(2)-xy-y^(2))dy=0`
From the separating of variables,
`(x^(2)-xy-y^(2))dy=-y^(2)dx`
`implies (dy)/(dx)=-(y^(2))/(x^(2)-xy-y^(2))`
`implies (dy)/(dx)=-(((y)/(x))^(2))/([1-(y)/(x)-((y)/(x))^(2)])`
which is a homogenous differential equation.


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