Manual Maple 2.2.2.mws

Comandos Úteis e Simples

Section 2.2: Resolvendo Equações

Session 2.2.2: fsolve

>    restart;

>    Digits := 20;

Digits := 20

>    p := x^5-x+1;

p := x^5-x+1

>    r := fsolve( p, x );

r := -1.1673039782614186843

>    subs( x=r, p );

-.4e-18

>    pseudozeros := fsolve( p, x, complex );

pseudozeros := -1.1673039782614186843, -.18123244446987538390-1.0839541013177106684*I, -.18123244446987538390+1.0839541013177106684*I, .76488443360058472603-.35247154603172624932*I, .764884433600584726...
pseudozeros := -1.1673039782614186843, -.18123244446987538390-1.0839541013177106684*I, -.18123244446987538390+1.0839541013177106684*I, .76488443360058472603-.35247154603172624932*I, .764884433600584726...
pseudozeros := -1.1673039782614186843, -.18123244446987538390-1.0839541013177106684*I, -.18123244446987538390+1.0839541013177106684*I, .76488443360058472603-.35247154603172624932*I, .764884433600584726...

>    map( evalf[1],[seq( abs(eval( p, x=z)), z=pseudozeros )]);

[.4e-18, .1e-18, .1e-18, .1e-19, .1e-19]

>    Digits := trunc(evalhf(Digits));

Digits := 14

>    X := fsolve( x*tan(x) - 1, x );

X := -.86033358901938

>    X*tan(X)-1;

0.

>    plot( [x*tan(x),1], x=-10..10, y=-5..5, discont=true, colour=black );

[Maple Plot]

>    X := fsolve( x*tan(x)-1, x=3);

X := 3.4256184594817

>    X*tan(X);

.99999999999990

>    X := fsolve( x*tan(x)-1, x=6);

X := 6.4372981791719

>    X*tan(X);

.99999999999966

>    Digits := 20;

Digits := 20

>    r := fsolve( x*tan(x)-1, x=1000*Pi );

r := 3141.5929718996364202

>    r*tan(r);

.99999999999994046653

>    r - evalf(1000*Pi);

.3183098431817e-3

>    1/%;

3141.5930780034739225

>    assume(n,integer);

>    T := subs( x=(n*Pi+delta), x*tan(x) );

T := (n*Pi+delta)*tan(n*Pi+delta)

>    T := series( T, delta );

T := series(n*Pi*delta+1*delta^2+1/3*n*Pi*delta^3+1/3*delta^4+2/15*n*Pi*delta^5+O(delta^6),delta,6)

>    solve( T=t, delta );

series(1/(n*Pi)*t+(-1/(n^3*Pi^3))*t^2+(-1/3*(-6+n^2*Pi^2)/n^5/Pi^5)*t^3+1/3*(-15+4*n^2*Pi^2)/n^7/Pi^7*t^4+1/5*(70-25*n^2*Pi^2+n^4*Pi^4)/n^9/Pi^9*t^5+O(t^6),t,6)

>    asympt( eval( convert( %, polynom ), t=1 ), n, 7 );

1/(n*Pi)-4/3*1/(n^3*Pi^3)+O(1/(n^5))

>   

>    restart;

>    sys := {x^2+y^2-1,25*x*y-12};

sys := {x^2+y^2-1, 25*x*y-12}

>    fsolve( sys, {x,y} );

{x = -.6000000000, y = -.8000000000}

>    fsolve( sys, {x=-1..0,y=0..1} );

fsolve({x^2+y^2-1, 25*x*y-12},{x, y},{x = -1 .. 0, y = 0 .. 1})

>    fsolve( sys, {x=0.2..1.2, y=0.2..1.2} );

{x = .8000000000, y = .6000000000}

>    fsolve( sys, {x=-1.2..-0.2, y=-1.2..-0.2} );

{x = -.6000000000, y = -.8000000000}

>