AP Calc AB - Mathematical Notations

∈

"is an element of..."
"is in the set..."
"is in the interval..."

∃

Existential Quantifier
"there exists..."

∀

Universal Qualifier
"for all..."

s.t.

"such that"

!

"unique"

∪

"union"/"or"
used when more than one interval is part of the solution

C

set of all complex numbers
{a+bi | a,b∈R}

R

set of all real numbers

R-Q

set of irrational numbers (π, e, "n" root of a prime number)

Q

set of all rational numbers
{a/b | a,b,∈Z..b≠0}

Z

set of all integers
(...-2,-1,0,1,2...)

N

set of natural numbers
(1,2,3,4...)

∀x∈R, s.t. x≠0, ∃!y∈R s.t. xy=1

For every non-zero "x" in the set of real number there exists a unique "y" in the set of real numbers such that "x" times "y" equals 1

∀x∈(0,1), ∃y∈(1,∞) s.t. y=1/x

For every "x" in the interval from 0 to 1 there exits a "y" in the interval from 1 to infinity such that "y" equals 1 divided by "x"