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Vector Algebra

Question
CBSEENMA12033038

Find a one parameter family of solutions of each of the following differential equation:
 (x y2 + 2x) dx + (x2 y + 2y) dy = 0

Solution

The given differential equation is
                (x y2 + 2x) dx + (x2 y + 2y) dy = 0
or       straight y left parenthesis straight x squared plus 2 right parenthesis space dx space equals space minus straight x left parenthesis straight y squared plus 2 right parenthesis space dx
therefore space space space space space fraction numerator straight y over denominator straight y squared plus 2 end fraction dy space equals negative fraction numerator straight x over denominator straight x squared plus 2 end fraction dx
Integrating, integral fraction numerator 2 straight y over denominator straight y squared plus 2 end fraction dy space equals negative integral fraction numerator 2 straight x over denominator straight x squared plus 2 end fraction dx
therefore space space space space space space log space left parenthesis straight y squared plus 2 right parenthesis space equals space minus log left parenthesis straight x squared plus 2 right parenthesis space plus space log space straight c space space space or space space space log space open square brackets left parenthesis straight y squared plus 2 right parenthesis space left parenthesis straight x squared plus 2 right parenthesis close square brackets space plus space log space straight c
therefore space space space space left parenthesis straight y squared plus 2 right parenthesis thin space left parenthesis straight x squared plus 2 right parenthesis space equals space straight c space is space the space required space solution.