hmerriman11

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3 years, 359 days

MaplePrimes Activity


These are questions asked by hmerriman11

I'm having trouble plotting a couple things. I have

eq := diff(y(x), x$3)+3*diff(y(x),x$2)+12*y(x);
soln := dsolve(eq, y(x));
soln := evalf(soln);
PartSoln1 := dsolve({eq, y(0) = a,y'(0) = 0,y''(0) = 0}, y(x));
curves := {seq(PartSoln1, a = -3 .. 3)};
Then when I try plot(curves, x = -1..5, y = -5..5); I get Warning, expecting only range variable x in expression PartSoln1 to be plotted but found name PartSoln1.

Also,
charEq := r^3+r+1 = 0;
soln := solve(charEq, r);
soln := [evalf(soln, 5)];
soln := map(Re, soln);

I tried a few things, but can't figure out how to plot charEq, including the real roots.

Thanks for any help,

Heather

I have an equation eq := diff(y(x), x$3)+3*diff(y(x), x$2)+12*y(x);

dsolve(eq, y(x)); gave me a general solution.

I tried to get a particular solution using dsolve({eq, y(0) = a, y'(0)=0, y"(0) = 0}, y(x));

But I got Error, (in dsolve) not a system with respect to the unknowns [y(x)].

Thank you for any help.

Heather

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