## 355 Reputation

11 years, 285 days

## re solve...

`restart:with( RealDomain ):#assume( x>0, y>0, x < y);solve({x/y = (1/128)*y, (1/16)*x = 16/y},{x,y});`
`{x = 8, y = 32}`

## Re: DEplot...

 > restart:
 > with(DEtools):
 > ode := diff(y(x),x) =2*y(x)*(y(x)-4);
 (1)
 > DEplot(ode,y(x),x=-1..1,y=-2..7.40,arrows=medium,linecolor=black);

## A possible way (pointplot)...

 > restart:with(plots):
 > p:=[[0.7,0.3000],[1,0.2000208010],[1.3,0.010]];
 (1)
 > display(pointplot(p,color=[red]),pointplot(p,connect=true),labels = ["K","(newton@@5)(.2)"]);
 >

## absolute error tolerance...

de1 := dsolve(d1, numeric,method = bvp,abserr=1*10^(-0));

abserr.mw

## e should be exp(1)...

f(x) := -(2*(exp(1)-1))*exp(-3*x)/exp(-3)+(3*exp(1)-2)*exp(-3*x)*x/exp(-3);

plot(f(x),x=1..10);

## syntax...

`restart:`
`ode := diff(f(x), x\$3)-(diff(f(x), x\$2))+2*(diff(f(x), x\$1));`
`ics:=D(f)(0)=0,f(0)=1,(D@D)(f)(0)=0;`
`dsolve({ode,ics});`
`                         f(x) = 1`

## shooting method but no dual solution...

Have a look.

Thanks

mprimesshootingmetho.mws

## this is what you are looking for???...

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