Whenever we are dealing with rational fractions.
We use the denominator below the numerator.
we had to do math that is denominator
Either: when given a fraction with a surd as the denominator, rationalising the denominator; Or, when given a fraction with a complex denominator, to make the denominator real.
Not necessarily. The denominator need not have any real zeros, for example x2+1. Not necessarily. The denominator need not have any real zeros, for example x2+1. Not necessarily. The denominator need not have any real zeros, for example x2+1. Not necessarily. The denominator need not have any real zeros, for example x2+1.
When reducing fractions to their simplest form the greatest common factor of their numerator and denominator must be found.
Unless you are an electrical engineer or a math teacher, every number you will ever use in a real world situation will be a real number.
Well, since there is no such thing as a sphare in the real world, it is a bit hard to tell what it can or cannot use.
Use the rules of division for complex numbers. Just divide 1 / (4 + 3i). This requires multiplying numerator and denominator of this fraction by (4 - 3i), to get a real number in the denominator.
All fractions (with whole numbers in the numerator and the denominator - zero in the denominator is not allowed) are rational numbers, and therefore also real numbers.
use a absolute value to represent a negative number in the real world
Vinculum
In a fraction, the numerator represent the part out of the denominator which represents the total. Neither need be rational (or even real).