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Vector Algebra

Question
CBSEENMA12032868

Verify that the function y = e–3x is a solution of the differential equation fraction numerator straight d squared straight y over denominator dx squared end fraction plus dy over dx minus 6 straight y space equals space 0

Solution

                  straight y space equals space straight e to the power of negative 3 straight x end exponent                                                                      ...(1)
therefore         dy over dx space equals space straight e to the power of negative 3 straight x end exponent. space left parenthesis negative 3 right parenthesis space space space space space space space or space space space space space dy over dx equals negative 3 straight e to the power of negative 3 straight x end exponent                ...(2)
         fraction numerator straight d squared straight y over denominator dx squared end fraction equals negative 3 space straight e to the power of negative 3 straight x end exponent. space left parenthesis negative 3 right parenthesis space space space or space space space fraction numerator straight d squared straight y over denominator dx squared end fraction space equals space 9 straight e to the power of negative 3 straight x end exponent                  ...(3)
L.H.S. = fraction numerator straight d squared straight y over denominator dx squared end fraction plus dy over dx minus 6 straight y space equals space 9 straight e to the power of negative 3 straight x end exponent minus 3 straight e to the power of 3 straight x end exponent minus 6 straight e to the power of negative 3 straight x end exponent space space space space space open square brackets because space of space left parenthesis 1 right parenthesis comma space left parenthesis 2 right parenthesis comma space left parenthesis 3 right parenthesis close square brackets
            = 0 - R.H.S.
therefore space space space straight y space equals straight e to the power of negative 3 straight x end exponent  is a solution of the differential equation
                        fraction numerator straight d squared straight y over denominator dx squared end fraction plus dy over dx minus 6 straight y space equals space 0