Show that the following differential equation is homogeneous and

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 Multiple Choice QuestionsShort Answer Type

191.

Solve the  differential equation:
straight x squared dy over dx space equals straight y left parenthesis straight x plus straight y right parenthesis.

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 Multiple Choice QuestionsLong Answer Type

192.

Solve the  differential equation:
left parenthesis straight y plus straight x right parenthesis space dy over dx space equals space straight y minus straight x.

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193.

Solve the following differential equation:
(y2 – x2) dy = 3 x y dx

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194. Show that the following differential equation is homogeneous and find a primitive of it. Derive the solution wherever possible:
(x - y) y' = x + 2 y 
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195. Show that the following differential equation is homogeneous and find a primitive of it. Derive the solution wherever possible:
(x2 + y2) y' = 8 x2 - 3 x y + 2 y2
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196. Show that the following differential equation is homogeneous and find a primitive of it. Derive the solution wherever possible:
(3 x y + y2) dx = (x2 + x y) dy
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197. Show that the following differential equation is homogeneous and find a primitive of it. Derive the solution wherever possible:
2 x y dx + (x2 + 2 y2) dy = 0


The given differential equation is
2 x y dx + (x2 + 2 y2) dy = 0    or      left parenthesis straight x squared plus 2 straight y squared right parenthesis space dy space equals space minus 2 xy space dx
therefore space space space space dy over dx space equals space minus fraction numerator 2 xy over denominator straight x squared plus 2 straight y squared end fraction
Put  y = v x so that dy over dx equals straight v plus straight x dv over dx

therefore space space space space space straight v plus straight x dv over dx equals negative fraction numerator 2. straight x. space straight v space straight x over denominator straight x squared plus 2 straight v squared straight x squared end fraction space space space or space space space straight v plus straight x dv over dx space equals space minus fraction numerator 2 straight v over denominator 1 plus 2 straight v squared end fraction
therefore space space space space space space straight x dv over dx equals negative fraction numerator 2 straight v over denominator 1 plus 2 straight v squared end fraction minus straight v space space space space space or space space space space space straight x dv over dx equals space fraction numerator negative 2 straight v minus straight v minus 2 straight v cubed over denominator 1 plus 2 straight v squared end fraction
therefore space space space space space straight x dv over dx space equals fraction numerator negative 3 straight v minus 2 straight v cubed over denominator 1 plus 2 straight v squared end fraction space space space space space space space rightwards double arrow space space space space space space fraction numerator 1 plus 2 straight v squared over denominator 3 straight v plus 2 straight v cubed end fraction dv space equals space minus 1 over straight x dx

Integrating, 1 third integral fraction numerator 3 plus 6 straight v squared over denominator 3 straight v plus 2 straight v cubed end fraction space equals space minus integral 1 over straight x dx
therefore space space space 1 third space log space open vertical bar 3 straight v space plus space 2 straight v cubed close vertical bar space equals space minus 3 space log space open vertical bar straight x close vertical bar space plus space 3 space log space open vertical bar straight c subscript 1 close vertical bar
therefore space space space log space open vertical bar 3 straight v plus 2 straight v cubed close vertical bar space plus space log space open vertical bar straight x close vertical bar cubed space equals space log space left parenthesis straight c right parenthesis
therefore space space space space open square brackets left parenthesis 3 space straight v plus space 2 straight v cubed right parenthesis space left parenthesis straight x right parenthesis close square brackets cubed space equals space straight c
therefore space space space open parentheses 3 straight y over straight x plus 2 straight y cubed over straight x cubed close parentheses space left parenthesis straight x cubed right parenthesis space equals straight c
or space space space 3 straight x squared straight y plus 2 straight y cubed space equals space straight c comma space which space is space required space solution. space
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198. Show that the following differential equation is homogeneous and find a primitive of it. Derive the solution wherever possible:
left parenthesis 2 straight x squared straight y plus straight y cubed right parenthesis space dx plus space left parenthesis xy squared minus 3 straight x cubed right parenthesis space dy space equals space 0
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 Multiple Choice QuestionsShort Answer Type

199. Show that the following differential equation is homogeneous and find a primitive of it. Derive the solution wherever possible:
straight x space straight y apostrophe space minus space straight y space plus space straight x space sin space space open parentheses straight y over straight x close parentheses space equals 0
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 Multiple Choice QuestionsLong Answer Type

200. Show that the following differential equation is homogeneous and find a primitive of it. Derive the solution wherever possible:
left parenthesis straight x plus 2 straight y right parenthesis space dx space minus space left parenthesis 2 straight x minus straight y right parenthesis space dy space equals space 0
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