Sollya User's Manual

Name:

numerator gives the numerator of an expression

Usage:

numerator(expr) : function -> function

Parameters:

expr represents an expression

Description:

If expr represents a fraction expr1/expr2, numerator(expr) returns the numerator of this fraction, i.e. expr1.

If expr represents something else, numerator(expr) returns the expression itself, i.e. expr.

Note that for all expressions expr, numerator(expr) / denominator(expr) is equal to expr.

Example 1:

> numerator(5/3);
5

Example 2:

> numerator(exp(x));
exp(x)

Example 3:

   > a = 5/3;
   > b = numerator(a)/denominator(a);
   > print(a);
   5 / 3
   > print(b);
   5 / 3

Example 4:

   > a = exp(x/3);
   > b = numerator(a)/denominator(a);
   > print(a);
   exp(x / 3)
   > print(b);
   exp(x / 3)

See also: denominator, rationalmode

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