Variablen

> restart;

> lsg:=solve( x^2-5*x+6=0, x );

> x:=lsg[1];

> solve( x^2-5*x+6=0, x );

Error, (in solve) a constant is invalid as a variable, 3

> x^2-5*x+6=0;

> x:='x';

> solve( x^2-5*x+6=0, x );

Interne Darstellung

> restart;

> x:=3:
assigned(x), assigned(a);

> a:=1: b:=2: c:=3:

> unassign('a, b, c');

> a,b,c;

> w:=1: x:=a^2+b^2: y:={a+b=5, a-b=1}: z:=array([1,2]):

> whattype(w), whattype(x), whattype(y), whattype(z);

> type(y,set);

> type(z,array);

> type(z,matrix);

anames, unames

> anames();

> unames();

> sort( select( x->length(x)<8, [anames()]) );

> Pi:=3.14;

Error, attempting to assign to `Pi` which is protected

assign

> restart;

> x:=2;

> y:='x'; z:='y';

> z;

> x:=3: z;

> x:=3;

> restart;

> a:=array(0..5);

> seq( assign(a[i],2^i), i=0..5);

> seq(a[i], i=0..5);

> seq( assign(a[i],2^i), i=0..5);

Error, (in assign) invalid arguments

> seq( assign( evaln(a[i]),3^i ), i=0..5);

> seq(a[i], i=0..5);

> restart;

> x:=y;

> assign(x, 3); x,y;

> restart;

> solve( {x+y=3, x-y=2} );

> assign(%);

> x,y;

eval mit Nebenbedingungen

> restart;

> eval( x^2 + 2*x*y + y^2, { x=2, y=3} );

> eval(sin(x)+cos(y),{x=y^2, y=x^2} );

> solve( {x^2+y^2=10, x+y=4});

> eval( x^2 + 2*x*y + y^2, %[1]);

assume

> restart;

> Re( expand((a+I*b)^2) );

> assume(a,real, b,real);

> Re( expand((a+I*b)^2) );

> sqrt(n^2);

> assume(n>0);

> sqrt(n^2);

> simplify(sqrt(x^2));

> simplify(sqrt(x^2),symbolic);

> n:='n':

> cos(n*Pi);

> assume(n,integer): cos(n*Pi);

> assume(n,odd): cos(n*Pi);

> restart;

> int(exp(-a*x^2), x=0..infinity);

Definite integration: Can't determine if the integral is convergent.

Need to know the sign of --> a

Will now try indefinite integration and then take limits.

> assume(a>=0): int(exp(-a*x^2), x=0..infinity);

> assume(x0>0):

> is(x0>-1), is(x0>1), is(x0,real), is(x0>x1);

> about(x0);

Originally x0, renamed x0~:

is assumed to be: RealRange(Open(0),infinity)

macro und alias

> restart;

> macro(s=solve): s(x^2-2);

> macro(s=sin): s(x^2-2);

> macro(s=1.2345): s:=3;

Error, invalid left hand side of assignment

> macro(s=s): s:=3;

> restart;

> alias(s=sin);

> sin(x);

> alias(f=f(x)): diff(f^2,x);

Verkettung mit ||

> restart;

> a||b||c;

> abc:=3;

> a||b||c;

> a||b||c:=4;

> a||b||c;

> b:=1: c:=2: a||b||c;

> a:=x: a||b||c;

> ``||a||b||c;

> cat(a,b,c);

> sum('x||i', i=0..5);

System- und Umgebungsvariablen

> Digits:=20: evalf(1/3);

> series(sin(x)/(1+x),x);

> Order:=10: series(sin(x)/(1+x),x);

> restart;

> interface(showassumed=2);

> assume(n,odd); sin(n*x);

>