Function: math[domainx] - determines the domain of a real-valued function

Calling Sequence:

domain(fn);

Parameters:

fn - a function in one real

Description:

domainx determines the real domain on which the function f is defined. Functions including logarithms or roots are evaluated, as well. f must not contain parameters.

The result is a range or a sequence of ranges. Further possible results are 'real' if RealRange(-infinity, infinity) or a numerical value a if f is defined at a.

As opposed to math/domain without the option 'singularity', discontinuities are acknowledged..

This function is part of the math package, and so can be used only after performing the command with(math) or with(math, domainx).

Special thanks goes to Jose I. Rodríguez González , Spain, for extending math/domain to math/domainx.

Examples:

> with(math, domainx):

> f := x -> (0.3*x^3-0.3*x^2-2.5*x+2.5)/abs(x-1);

[Maple Math]

> domainx(f(x));

[Maple Math]

> f := x -> 3/2*sqrt(abs(x^2-1));

[Maple Math]

> domainx(f(x));

[Maple Math]

> f := x -> sqrt(x^3+4*x^2+4*x);

[Maple Math]

> domainx(f(x));

[Maple Math]

> f := x -> sqrt(x^3-4*x);

[Maple Math]

> domainx(f(x));

[Maple Math]

> domainx(ln(x));

[Maple Math]

See Also:

convert/range , math/sortranges , math/fnull , math/extrema , math/inflection , iscont , discont .

Version History:

Version 1.0 as of December 30, 1997

Version 2.0 as of June 09, 1998