dy/dx=2y/x
dy/y=2.dx/x
ln(y)=2ln(x)+ln(c)
y=c.x^2
y(1)=2
2=c.1
c=2
y=2x^2
2007-05-05 20:37:26
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answer #1
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answered by gudspeling 7
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i'm assuming that your first equation has an blunders in it and your 2nd one is authentic. it is, the final equation is (x^2 + 3xy +y^2)dx - x^2 dy = 0 is the final assertion. it is homogeneous. enable y = v x, so dy = x dv + v dx. replace for v, removing y and dy everywhere. Then simplify your equation. Then it is going to likely be accessible to split variables. Separate them, combine and remedy for v and finally for y.
2016-12-28 14:49:54
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answer #2
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answered by digiambattist 3
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dy/dx=2y/x
dy/y=2dx/x
Integrating both sides
lnlyl=2lnlxl+lnc
No harm made if I put
instead c=lnc
lnlyl=ln(cx^2)
y=cx^2
I ignore abs.value of y
because c can take
both possitive or negative
values,
For x=1-->y=2
-->c=2
Then y=2x^2
2007-05-05 20:37:21
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answer #3
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answered by katsaounisvagelis 5
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dy/dx=2y/x
dy/y=2.dx/x
ln(y)=2ln(x)+ln(c)
y=c.x^2
but given, y(1)=2
2=c.1
c=2
y=2x^2
2007-05-07 20:42:12
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answer #4
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answered by PREM K 1
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dy/dx = 2y / x
(1/2).∫ (1/y).dy = ∫ (1/x).dx
(1/2).log y = log x + C
(1/2).(log 2) = log1 + C
C = (1/2) log 2
(1/2) log y = log x + (1/2) log 2
log y = 2 log x + log 2
log y = log x² + log 2
y = 2x²
2007-05-05 20:46:27
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answer #5
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answered by Como 7
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