Sections 1.1 - 1.5 Flashcards
Complex Numbers
Have the form a+bi in which a and b are real numbers and i = the square root of -1
Real Numbers
Numbers that have points on the number line
Imaginary Numbers
Square roots of negative numbers, which have no points on the number line.
Negative Numbers
Numbers less than 0
Zero
Neither positive nor negative
Positive Numbers
Numbers greater than 0
Rational Numbers
Can be expressed exactly as a ratio of 2 integers
Irrational Numbers
Cannot be expressed exactly as a ratio of 2 integers, but are real numbers
Integers
Whole numbers and their opposites
Nonintegers
Fractions, or numbers between the integers
Radicals
Involve square roots, cube roots, etc. of integers
Transcendental Numbers
Cannot be expressed as roots of integers (pi)
Odd Numbers
Numbers not divisible by 2
Even Numbers
Numbers divisible by 2
Digits
Numbers from which the numerals are made (0, 1, 2, 3, 4, 5, 6, 7, 8, 9)
Natural / Counting Numbers
Positive integers or counting numbers
Field Axioms
The properties of algebra
Definition of Subtraction
a - b = a + (-b)
Definition of Division
a/b = a times 1/b
Closure
The sum / product of any two members of a set must belong to the given set.
Closure under addition
a + b is always a unique, real number
Closure under multiplication
ab is always a unique, real number
Commutativity
Changes the order of the operation
Commutativity for addition
a + b = b + a
Commutativity for multiplication
ab = ba
Associativity
Changes the groupings and not the order
Associativity for addition
(a + b) + c = a + (b + c)
Associativity for multiplication
(ab)c = a(bc)
Inverses
The set must contain the opposite and the reciprocal to be a field.
Inverse of Addition
a + (-a) = 0