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:

Assume_pos

-- Option variable: assume_pos Default value: false

When assume_pos is true and the sign of a parameter <x> cannot be determined from the current context or other considerations, sign and asksign (<x>) return true. This may forestall some automatically-generated asksign queries, such as may arise from integrate or other computations.

assume_pos:true;
liste:makelist(i,i,-5,5);
liste^2;
solve(x^2+8*x+15=0);

By default, a parameter is <x> such that symbolp (<x>) or subvarp (<x>). The class of expressions considered parameters can be modified to some extent via the variable assume_pos_pred.

sign and asksign attempt to deduce the sign of expressions from the sign of operands within the expression. For example, if a and b are both positive, then a + b is also positive.

However, there is no way to bypass all asksign queries. In particular, when the asksign argument is a difference <x> - <y> or a logarithm log(<x>), asksign always requests an input from the user, even when assume_pos is true and assume_pos_pred is a function which returns true for all arguments.

There are also some inexact matches for assume_pos. Try ?? assume_pos to see them.

(%o1)                                true
(%i2) 

Related Examples

assume_pos-expand-factor-integrate-sqrt-true

assume_pos:true;

t:integrate(1/(x*sqrt...

expand(factor(t));

Calculate

assume_pos-makelist-true

assume_pos:true;

makelist(i,i,-5,5);

Calculate

assume_pos-factor-integrate-sqrt-true

assume_pos:true;

t:integrate(1/(x*sqrt...

factor(t);

Calculate

assume_pos-makelist-true

assume_pos:true;

makelist(i,i,-5,5);

Calculate

assume_pos-makelist-true

assume_pos:true;

makelist(i,i,-5,5);

Calculate

assume_pos-integrate-true

assume_pos:true;

f[0](x):=1/(1+x)^3;

f[n](x):=integrate(f[...

Calculate

assume_pos-solve-true

assume_pos:true;

solve(x^2+8*x+15=0,x);

Calculate

assume_pos-false-makelist-solve

assume_pos:false;

liste:makelist(i,i,-5...

liste^2;

Calculate

assume_pos-solve-true

assume_pos:true;

solve(x^2+8*x+15=0,x);

Calculate

assume_pos-makelist-solve-true

assume_pos:true;

liste:makelist(i,i,-5...

liste^2;

Calculate