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Vector Algebra

Question
CBSEENMA12032959

Form the differential equation of the following family of curves:
x y = A ex + B e–x + x2 

Solution
The equation of the family of curves is
x y = A ex + B e–x + x2                                ...(1)
Differentiating both sides w.r.t. x, we get,
             straight x dy over dx plus straight y space.1 space equals space Ae to the power of straight x minus Be to the power of negative straight x end exponent plus 2 straight x
Again differentiating both sides w.r.t. x, we get,
             straight x fraction numerator straight d squared straight y over denominator dx squared end fraction plus dy over dx.1 plus dy over dx space equals space straight A space straight e to the power of straight x plus Be to the power of negative straight x end exponent plus 2
or      straight x fraction numerator straight d squared straight y over denominator dx squared end fraction plus 2 dy over dx space equals space xy space minus straight x squared plus 2                       open square brackets because space of space left parenthesis 1 right parenthesis close square brackets
which is required differential equation.