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- April 22nd 2009, 03:03 AM #1

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- Feb 2009
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## Help please

If I have the second order differential equation

y'' + y = 0

The auxilliary equation is

m^2 + m = 0

The two solutions are therefore

m = 0, -1

so

y = A*exp(0*x) + B*exp(-1*x)

Is this correct?

My notes say the solution is

y = C1*cos(x) + C2*sin(x)

can anyone explain please

- April 22nd 2009, 03:45 AM #2

- April 22nd 2009, 04:02 AM #3

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- Feb 2009
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