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Vector Algebra

Question
CBSEENMA12033031

Find the general solution of each of the following equations:
left parenthesis straight x plus 2 right parenthesis space dy over dx space equals space straight x squared plus 4 straight x minus 9


Solution
The given differential equation is
             left parenthesis straight x plus 2 right parenthesis space dy over dx space equals space straight x squared plus 4 straight x minus 9    or    dy over dx space equals space fraction numerator straight x squared plus 4 straight x minus 9 over denominator straight x plus 2 end fraction
Separating the variables, we get
                           dy space equals space open parentheses fraction numerator straight x squared plus 4 straight x minus 9 over denominator straight x plus 2 end fraction close parentheses space dx
or                 dy space equals open parentheses fraction numerator straight x squared plus 4 straight x minus 9 over denominator straight x plus 2 end fraction close parentheses dx
or         dy space equals space open parentheses straight x plus 2 minus fraction numerator 13 over denominator straight x plus 2 end fraction close parentheses dx
Integrating, 
               straight y equals straight x squared over 2 plus 2 straight x minus 13 space log space open vertical bar straight x plus 2 close vertical bar space plus space straight c
which is required solution. 
                                      straight x plus 2 space space fraction numerator straight x plus 2 over denominator long division enclose straight x squared plus 4 straight x minus 9 end enclose end fraction
space space space space space space space space space space space space space space space space straight x squared plus 2 straight x
space space space space space space space space space space space space space space space space minus space space minus
space space space space space space space space space space space space space _________
space space space space space space space space space space space space space 2 straight x space space minus space 9
space space space space space space space space space space space space space 2 straight x space plus space 4
space space space space space space space space space space space space space space minus
space space space space space space space space space space space space space _________
space space space space space space space space space space space space space space space space space space space space space space space space 13





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