Number Systems, Decimals And Rational Powers Flashcards
(chalkboard) R
Real numbers
real numbers
all numbers on a number line.
(chalkboard) Z
The integers
The integers
the subset of the real numbers given by
{…,−2,−1,0,1,2,…}.
N
natural numbers
natural numbers
the subset of the integers given by {1, 2, 3 . . .}.
(chalkboard) Q
rational numbers
rational numbers
the subset of the real numbers givenby{qp |p,q∈Z}
(chalkboard) I
irrational numbers
irrational numbers
the real numbers that are not rational
root2
The number root2 is irrational
Between any two rationals…
there is another rational
Let a be a rational number, and b an irrational.
Then a + b is…
irrational
Let a be a rational number, and b an irrational.
If a does not equal 0, then ab is…
Irrational
Form of a decimal expression
x = a0.a1a2a3 …
Which numbers have a decimal expression?
Every real number
What is the condition for a periodic decimal expansion?
A real number has periodic decimal expansion if and only if it is rational.
The form of a periodic decimal expansion? is called periodic if it has the form
a0.a1 …anb1 …bkb1 …bkb1 … (1)
for a0 ∈ Z and a1,…,an,b1,…,bk ∈ {0,1,…,9}. We abbreviate the expression in (1) by
a0.a1 …anb1 …bk.
Slide 19 decimals
The rest of the decimals slides
PowerPoint presentation
y^n = x proposition
Let n be a positive integer. If x is a positive real number, then there is a unique positive number y such that y^n = x.
The rest of nth roots etc
PowerPoint presentation