# derive-it.com

A radian is defined as follows. $360^{\circ} = 2 \pi$ radians. Dividing both sides by $2\pi$, one radian is: $\frac{180}{\pi}^{\circ} = 1$ radian.

• ## Exponents

The following rules apply for exponents that are positive integers. The justification is sketched here.   These rules are also said to apply for exponents that are not positive integers–that is, zero and negative integers. If $p$ and $q$ are rational numbers, they are also said to apply. Finally, if $p$ and…

• ## Irrational Numbers

Are rational numbers the only numbers? The continuity of real numbers is an assumption in the Cantor-Dedekind axiom . The idea of continuity brings up the possibility of a different type of number called an irrational number that is, simply, not a rational number. So, if a number is not a rational number, it is…

• ## Definition of a Sequence

The title of Section 2 in book  is Sequences of rational numbers. At the beginning of this section, a definition is provided for a sequence, and I quote it here. Definition. If, by means of any suitable process of construction, we can form successively a first, a second, a third, … (rational) number and…