> |
A Maple Demonstration of
Convergence of Power Series
prepared by
Douglas B. Meade (meade@math.sc.edu)
12 November 2003
> |
> | restart; |
> | with( plots ): |
Warning, the name changecoords has been redefined
> |
Auxiliary Procedure Definitions (execute, but do not modify)
> | AnimateSeries := proc( series, |
> | domain::name=range(constant), |
> | psums::list(nonnegint) ) |
> | local NULL |
> | , F # limit of infinite sum |
> | , P # final plot data structure [returned] |
> | , plot_opts # optional arguments to plot command |
> | ; |
> | if nargs>3 |
> | then plot_opts := args[4..nargs] |
> | else plot_opts := NULL |
> | end if; |
> | if nops(series)=2 and op(0,series)<>`Sum` |
> | then |
> | error "invalid first argument, must an unevaluated series, received", |
> | series |
> | end if; |
> | F := value( series ); |
> | P := display( [seq( |
> | plot( [subsop([2,2,2]=N,series), F ], |
> | domain, plot_opts, title="Partial Sum: N="||N ), |
> | N=psums )], |
> | insequence=true ); |
> | return P |
> | end proc: |
> |
> | list_N1 := [ k $ k=0..16 ]; # consecutive integers |
> | list_N2 := [ 2*k $ k=0..10 ]; # even |
> | list_N3 := [ 2^k $ k=0.. 8 ]; # powers of 2 |
> |
Example 1
> | Series1 := Sum( x^k, k=0..infinity ); |
> | AnimateSeries( Series1, x=-2..2, list_N3, y=-10..100, discont=true ); |
> |
Example 2
> | Series2 := Sum( (-1)^n*x^n/n, n=1..infinity ); |
> | AnimateSeries( Series2, x=-2..2, list_N3, y=-10..100, discont=true ); |
> |
Example 3
> | Series3 := Sum( n*x^(n-1), n=1..infinity ); |
> | AnimateSeries( Series3, x=-2..2, list_N3, y=-20..100, discont=true ); |
> |
Example 4
> | Series4 := Sum( (-1)^n*x^(2*n)/(2*n)!, n=0..infinity ); |
> | AnimateSeries( Series4, x=-5*Pi..5*Pi, list_N1, y=-2..2, discont=true ); |
> |
Example 5
> | Series5 := Sum( (-(x+x^2))^n, n=0..infinity ); |
> | AnimateSeries( Series5, x=-5..5, list_N1, y=0..2, discont=true ); |
> |
> | solve( abs(x+x^2) < 1, {x} ); |
> | plot( [abs(x+x^2),1], x=-3..3 ); |
> |
Example 6
> | Series6 := Sum( (-1)^n*x^n/n, n=1..infinity ); |
> | AnimateSeries( Series6, x=-5..5, list_N1, y=-2..2, discont=true ); |
> |
Example 7
> | Series7 := Sum( n*(n-1)*x^(n-1), n=2..infinity ); |
> | AnimateSeries( Series7, x=-3..3, list_N2, y=-10..10, discont=true ); |
> |
> | value( Series7 ); |
> |
Example 8
> | Series8 := Sum( (x-5)^n/(2^n*n*(n+1)), n=1..infinity ); |
> | AnimateSeries( Series8, x=0..8, list_N3, y=-4..20, discont=true ); |
> |
> | value( Series8 ); |
> |
> |