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Vector Algebra

Question
CBSEENMA12032949

Form the differential equation of the family of curves
straight y equals Ae to the power of Bx
where A and B are constants.

Solution
The given equation is
                         straight y space equals space straight A space straight e to the power of Bx                                        ...(1)
therefore space space space space dy over dx space equals space straight A space straight B space straight e to the power of Bx space space space space space space space space or space space space space space dy over dx space equals space straight B space straight y              ...(2)
                                                                       open square brackets because space of space left parenthesis 1 right parenthesis close square brackets
therefore space space space fraction numerator straight d squared straight y over denominator dx squared end fraction space equals space straight B dy over dx                                                   ...(3)
From (2) and (3),  dy over dx space equals space fraction numerator straight y begin display style fraction numerator straight d squared straight y over denominator dx squared end fraction end style over denominator begin display style dy over dx end style end fraction
or              straight y fraction numerator straight d squared straight y over denominator dx squared end fraction space equals open parentheses dy over dx close parentheses squared which is the required differential equation.