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Vector Algebra

Question
CBSEENMA12033060

Solve:
straight y space logydx space minus space straight x space dy space equals space 0



 

Solution
The given differential equation is
  y log y dx - x dy = 0    or   y log y dx =  x dy
or          fraction numerator 1 over denominator straight y space log space straight y end fraction dy space equals space 1 over straight x dx
Integrating,     integral fraction numerator begin display style 1 over straight y end style over denominator log space straight y end fraction dy space equals space integral 1 over straight x dx
therefore space space space space space space space space log space open vertical bar log space straight y close vertical bar space equals space log space open vertical bar straight x close vertical bar space plus space log space straight A
therefore space space space space space space space space log space open vertical bar log space straight y close vertical bar space minus space log space open vertical bar straight x close vertical bar space equals space log space straight A
therefore space space space space log space open parentheses fraction numerator open vertical bar log space straight y close vertical bar over denominator open vertical bar straight x close vertical bar end fraction close parentheses space equals space log space straight A
therefore space space space space space space space space space space space space open vertical bar fraction numerator log space straight y over denominator straight x end fraction close vertical bar space equals space straight A space space or space space space space fraction numerator log space straight y over denominator straight x end fraction space equals space plus-or-minus space straight A
therefore space space space space space space space space fraction numerator log space straight y over denominator straight x end fraction space equals space straight c comma space space space where space straight c space equals space plus-or-minus straight A
or space space space space space space space log space straight y space equals space straight c space straight x space space space space space space space rightwards double arrow space space space space straight y space equals space straight e to the power of cx space is space required space solution.

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