# 16-19

> MODEL := diff( y(t), t$2 ) + p*diff(y(t), t ) + q*y(t) = cos(omega*t);

> PAR16 := { p=5, q=3, omega=1 };

> PAR17 := { p=1, q=3, omega=1 };

> PAR18 := { p=5, q=1, omega=3 };

> PAR19 := { p=1, q=1, omega=3 };

> VAR := { y(t) } ;

>

> ICa := y(0)= 1, D(y)(0)=-1;

> ICb := y(0)= 0, D(y)(0)= 0;

> ICc := y(0)=-1, D(y)(0)= 1;

> for n from 16 to 19 do

> SOLN.n := [ rhs( dsolve( { subs(PAR.n,MODEL), ICa }, VAR )),

> rhs( dsolve( { subs(PAR.n,MODEL), ICb }, VAR )),

> rhs( dsolve( { subs(PAR.n,MODEL), ICc }, VAR )) ]:

> PLOT.n := plot( SOLN.n, t=0..8*Pi );

> od:

> display( [ seq( PLOT.n, n=16..19 ) ], insequence=true );

>

Thus, #16 corresponds with (iii), #17 corresponds with (ii), #18 corresponds with (i), and #19 corresponds with (iv).

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