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Differential Equations

Question
CBSEENMA12033189

Solve:
dy over dx plus 2 straight y space equals space sin space 5 straight x

Solution
The given differential equation is 
                    dy over dx plus 2 straight y space equals space sin space 5 straight x
Comparing it with dy over dx plus Py space equals space straight Q comma space we space get comma
                       P = 2,   Q = sin 5x
         integral straight P space dx space equals space integral 2 space dx space equals 2 straight x
            straight I. straight F. space equals space straight e to the power of integral straight P space dx end exponent space equals space straight e to the power of 2 straight x end exponent
therefore solution of differential equation is
                          straight y space straight e to the power of integral straight P space dx end exponent space equals space integral straight Q space straight e to the power of integral straight P space dx end exponent dx plus straight c
or                 straight y space straight e to the power of 2 straight x end exponent space equals space integral space sin space 5 straight x. space straight e to the power of 2 straight x end exponent plus straight c
or                 ye to the power of 2 straight x end exponent space equals space fraction numerator 1 over denominator square root of 4 plus 25 end root end fraction straight e to the power of 2 straight x end exponent space sin space open parentheses 5 straight x minus tan to the power of negative 1 end exponent 5 over 2 close parentheses plus straight c space space space space space space space space space space space space space space space space space
                               open square brackets because space space integral straight e to the power of ax sin space bx space dx space equals space fraction numerator 1 over denominator square root of straight a squared plus straight b squared end root end fraction space straight e to the power of ax space sin space open parentheses bx minus tan to the power of negative 1 end exponent straight b over straight a close parentheses close square brackets
or               straight y space equals space fraction numerator 1 over denominator square root of 29 end fraction sin space open parentheses 5 straight x minus space tan to the power of negative 1 end exponent 5 over 2 close parentheses plus space straight c space straight e to the power of negative 2 straight x end exponent

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