Sponsored links: Algebra eBooks
 

Help Index

A

B

C

D

E

F

G

H

I

J

K

L

M

N

O

P

Q

R

S

T

U

V

W

X

Y

Z

The Maxima on-line user's manual

Algebra Calculator

Search:

Eliminate Calculator

Eliminate

Function: eliminate ([<eqn_1>, ..., <eqn_n>], [<x_1>, ..., <x_k>]) Eliminates variables from equations (or expressions assumed equal to zero) by taking successive resultants. This returns a list of <n> - <k> expressions with the <k> variables <x_1>, ..., <x_k> eliminated. First <x_1> is eliminated yielding <n> - 1 expressions, then x_2 is eliminated, etc. If <k> = <n> then a single expression in a list is returned free of the variables <x_1>, ..., <x_k>. In this case solve is called to solve the last resultant for the last variable.

fpprintprec: 2;
declare(Vgs,real);
assume(Vgs<0,Vgs>Vp);
e1: id = idss*(1-Vgs/Vp)^2;
e2: id = (Vg-Vgs)/Rs;
e3: solve(eliminate([e1,e2],[id]),Rs);
e4: solve(e1,Vgs);
[ idss, Vp, Vg ]: [10e-03,-2.2,0];
vgslst: map(rhs,ev(e4,id=idss/2));
vgslst: sublist(vgslst,lambda([x],is(x>Vp) and is(x<0)));
vgsq: first(vgslst);
c1: e3,Vgs=vgsq;
ev(e2,[Rs=560]);
ev([e1,e2],c1);
p:append( [ev(e2,[Rs=560])], ev([e1,e2],c1) );
plot2d(map(rhs,p),[Vgs,Vp,0],[legend,"Rs=560","Id","Rs=optimal"]);

Example:

          (%i1) expr1: 2*x^2 + y*x + z;
                                                2
          (%o1)                    z + x y + 2 x
          (%i2) expr2: 3*x + 5*y - z - 1;
          (%o2)                  - z + 5 y + 3 x - 1
          (%i3) expr3: z^2 + x - y^2 + 5;
                                    2    2
          (%o3)                    z  - y  + x + 5
          (%i4) eliminate ([expr3, expr2, expr1], [y, z]);
                       8         7         6          5          4
          (%o4) [7425 x  - 1170 x  + 1299 x  + 12076 x  + 22887 x

3 2 - 5154 x - 1291 x + 7688 x + 15376]

(%o1)                                true
(%i2) 

Eliminate Example

Related Examples

eliminate-facsum-ratsimp

mix(x0, x1, t) := x0*...

bez2(x0,x1,x2, t):= m...

bez3(x0,x1,x2,x3,t):=...

Calculate

eliminate-ratsimp

mix(x0, x1, t) := x0*...

bez2(x0,x1,x2, t):= m...

bez3(x0,x1,x2,x3,t):=...

Calculate

eliminate-false-logexpand-logsimp

logexpand: false;

logsimp: false;

eq1: Va = Vin - Rsh*I...

Calculate

eliminate-expand

Ie00:(Id*pa_dd+Ic*pa_...

Ie01:(Id*pa_cd+Ic*pa_...

Ie02:(Id*pa_bd+Ic*pa_...

Calculate

eliminate

eq1:mka*o1/100+mko=o2;

eq2:mka+mko=100;

eliminate([eq1,eq2],[...

Calculate

eliminate

expr1: x * (a + c) + ...

expr2: x * (a + c) + ...

eliminate ([expr2, ex...

Calculate

eliminate

expr1: x*(a+b)+y*a+z*...

expr2: y*a+z*b=n;

expr3: 0;

Calculate

eliminate

expr1: x*(a+b)+y*a+z*b;

expr2: y*a;

expr3: z*b;

Calculate

eliminate

eq1:x=z+y;

eq2:z^2=x+1;

eliminate([eq1,eq2],[...

Calculate

eliminate-linsolve-sqrt

a:[U1 = (a1 + b1)*sqr...

b:eliminate(a,[I1,I2,...

jednacina1:b2 - b1 + ...

Calculate