text
stringlengths
2
2.33k
source
stringclasses
826 values
An explicit formula can be used to find the number of terms in a sequence. SeeExample 6.
https://openstax.org/books/college-algebra-2e/pages/9-key-concepts
In application problems, we sometimes alter the explicit formula slightly toan=a0+dn.an=a0+dn.SeeExample 7.
https://openstax.org/books/college-algebra-2e/pages/9-key-concepts
A geometric sequence is a sequence in which the ratio between any two consecutive terms is a constant.
https://openstax.org/books/college-algebra-2e/pages/9-key-concepts
The constant ratio between two consecutive terms is called the common ratio.
https://openstax.org/books/college-algebra-2e/pages/9-key-concepts
The common ratio can be found by dividing any term in the sequence by the previous term. SeeExample 1.
https://openstax.org/books/college-algebra-2e/pages/9-key-concepts
The terms of a geometric sequence can be found by beginning with the first term and multiplying by the common ratio repeatedly. SeeExample 2andExample 4.
https://openstax.org/books/college-algebra-2e/pages/9-key-concepts
A recursive formula for a geometric sequence with common ratiorris given byan=ran–1an=ran–1forn≥2n≥2.
https://openstax.org/books/college-algebra-2e/pages/9-key-concepts
As with any recursive formula, the initial term of the sequence must be given. SeeExample 3.
https://openstax.org/books/college-algebra-2e/pages/9-key-concepts
An explicit formula for a geometric sequence with common ratiorris given byan=a1rn–1.an=a1rn–1.SeeExample 5.
https://openstax.org/books/college-algebra-2e/pages/9-key-concepts
In application problems, we sometimes alter the explicit formula slightly toan=a0rn.an=a0rn.SeeExample 6.
https://openstax.org/books/college-algebra-2e/pages/9-key-concepts
The sum of the terms in a sequence is called a series.
https://openstax.org/books/college-algebra-2e/pages/9-key-concepts
A common notation for series is called summation notation, which uses the Greek letter sigma to represent the sum. SeeExample 1.
https://openstax.org/books/college-algebra-2e/pages/9-key-concepts
The sum of the terms in an arithmetic sequence is called an arithmetic series.
https://openstax.org/books/college-algebra-2e/pages/9-key-concepts
The sum of the firstnnterms of an arithmetic series can be found using a formula. SeeExample 2andExample 3.
https://openstax.org/books/college-algebra-2e/pages/9-key-concepts
The sum of the terms in a geometric sequence is called a geometric series.
https://openstax.org/books/college-algebra-2e/pages/9-key-concepts
The sum of the firstnnterms of a geometric series can be found using a formula. SeeExample 4andExample 5.
https://openstax.org/books/college-algebra-2e/pages/9-key-concepts
The sum of an infinite series exists if the series is geometric with–1<r<1.–1<r<1.
https://openstax.org/books/college-algebra-2e/pages/9-key-concepts
If the sum of an infinite series exists, it can be found using a formula. SeeExample 6,Example 7, andExample 8.
https://openstax.org/books/college-algebra-2e/pages/9-key-concepts
An annuity is an account into which the investor makes a series of regularly scheduled payments. The value of an annuity can be found using geometric series. SeeExample 9.
https://openstax.org/books/college-algebra-2e/pages/9-key-concepts
If one event can occur inmmways and a second event with no common outcomes can occur innnways, then the first or second event can occur inm+nm+nways. SeeExample 1.
https://openstax.org/books/college-algebra-2e/pages/9-key-concepts
If one event can occur inmmways and a second event can occur innnways after the first event has occurred, then the two events can occur inm×nm×nways. SeeExample 2.
https://openstax.org/books/college-algebra-2e/pages/9-key-concepts
A permutation is an ordering ofnnobjects.
https://openstax.org/books/college-algebra-2e/pages/9-key-concepts
If we have a set ofnnobjects and we want to chooserrobjects from the set in order, we writeP(n,r).P(n,r).
https://openstax.org/books/college-algebra-2e/pages/9-key-concepts
Permutation problems can be solved using the Multiplication Principle or the formula forP(n,r).P(n,r).SeeExample 3andExample 4.
https://openstax.org/books/college-algebra-2e/pages/9-key-concepts
A selection of objects where the order does not matter is a combination.
https://openstax.org/books/college-algebra-2e/pages/9-key-concepts
Givennndistinct objects, the number of ways to selectrrobjects from the set isC(n,r)C(n,r)and can be found using a formula. SeeExample 5.
https://openstax.org/books/college-algebra-2e/pages/9-key-concepts
A set containingnndistinct objects has2n2nsubsets. SeeExample 6.
https://openstax.org/books/college-algebra-2e/pages/9-key-concepts
For counting problems involving non-distinct objects, we need to divide to avoid counting duplicate permutations. SeeExample 7.
https://openstax.org/books/college-algebra-2e/pages/9-key-concepts
(nr)(nr)is called a binomial coefficient and is equal toC(n,r).C(n,r).SeeExample 1.
https://openstax.org/books/college-algebra-2e/pages/9-key-concepts
The Binomial Theorem allows us to expand binomials without multiplying. SeeExample 2.
https://openstax.org/books/college-algebra-2e/pages/9-key-concepts
We can find a given term of a binomial expansion without fully expanding the binomial. SeeExample 3.
https://openstax.org/books/college-algebra-2e/pages/9-key-concepts
Probability is always a number between 0 and 1, where 0 means an event is impossible and 1 means an event is certain.
https://openstax.org/books/college-algebra-2e/pages/9-key-concepts
The probabilities in a probability model must sum to 1. SeeExample 1.
https://openstax.org/books/college-algebra-2e/pages/9-key-concepts
When the outcomes of an experiment are all equally likely, we can find the probability of an event by dividing the number of outcomes in the event by the total number of outcomes in the sample space for the experiment. SeeExample 2.
https://openstax.org/books/college-algebra-2e/pages/9-key-concepts
To find the probability of the union of two events, we add the probabilities of the two events and subtract the probability that both events occur simultaneously. SeeExample 3.
https://openstax.org/books/college-algebra-2e/pages/9-key-concepts
To find the probability of the union of two mutually exclusive events, we add the probabilities of each of the events. SeeExample 4.
https://openstax.org/books/college-algebra-2e/pages/9-key-concepts
The probability of the complement of an event is the difference between 1 and the probability that the event occurs. SeeExample 5.
https://openstax.org/books/college-algebra-2e/pages/9-key-concepts
In some probability problems, we need to use permutations and combinations to find the number of elements in events and sample spaces. SeeExample 6.
https://openstax.org/books/college-algebra-2e/pages/9-key-concepts
0 ! = 1 1 ! = 1 n ! = n ( n − 1 ) ( n − 2 ) ⋯ ( 2 ) ( 1 ) , for n ≥ 2 0 ! = 1 1 ! = 1 n ! = n ( n − 1 ) ( n − 2 ) ⋯ ( 2 ) ( 1 ) , for n ≥ 2
https://openstax.org/books/college-algebra-2e/pages/9-key-equations
a n = a n − 1 + d , n ≥ 2 a n = a n − 1 + d , n ≥ 2
https://openstax.org/books/college-algebra-2e/pages/9-key-equations
a n = a 1 + d ( n − 1 ) a n = a 1 + d ( n − 1 )
https://openstax.org/books/college-algebra-2e/pages/9-key-equations
a n = r a n − 1 , n ≥ 2 a n = r a n − 1 , n ≥ 2
https://openstax.org/books/college-algebra-2e/pages/9-key-equations
a n = a 1 r n − 1 a n = a 1 r n − 1
https://openstax.org/books/college-algebra-2e/pages/9-key-equations
S n = n ( a 1 + a n ) 2 S n = n ( a 1 + a n ) 2
https://openstax.org/books/college-algebra-2e/pages/9-key-equations
S n = a 1 ( 1 − r n ) 1 − r , r ≠1 S n = a 1 ( 1 − r n ) 1 − r , r ≠1
https://openstax.org/books/college-algebra-2e/pages/9-key-equations
S n = a 1 1 − r , r ≠1 S n = a 1 1 − r , r ≠1
https://openstax.org/books/college-algebra-2e/pages/9-key-equations
P ( n , r ) = n ! ( n − r ) ! P ( n , r ) = n ! ( n − r ) !
https://openstax.org/books/college-algebra-2e/pages/9-key-equations
C ( n , r ) = n ! r ! ( n − r ) ! C ( n , r ) = n ! r ! ( n − r ) !
https://openstax.org/books/college-algebra-2e/pages/9-key-equations
( x + y ) n = ∑ k − 0 n ( n k ) x n − k y k ( x + y ) n = ∑ k − 0 n ( n k ) x n − k y k
https://openstax.org/books/college-algebra-2e/pages/9-key-equations
( r + 1 ) t h ( r + 1 ) t h term of a binomial expansion
https://openstax.org/books/college-algebra-2e/pages/9-key-equations
P ( E ) = n ( E ) n ( S ) P ( E ) = n ( E ) n ( S )
https://openstax.org/books/college-algebra-2e/pages/9-key-equations
P ( E ∪ F ) = P ( E ) + P ( F ) − P ( E ∩ F ) P ( E ∪ F ) = P ( E ) + P ( F ) − P ( E ∩ F )
https://openstax.org/books/college-algebra-2e/pages/9-key-equations
P ( E ∪ F ) = P ( E ) + P ( F ) P ( E ∪ F ) = P ( E ) + P ( F )
https://openstax.org/books/college-algebra-2e/pages/9-key-equations
P ( E ' ) = 1 − P ( E ) P ( E ' ) = 1 − P ( E )
https://openstax.org/books/college-algebra-2e/pages/9-key-equations
Addition Principle : if one event can occur inmmways and a second event with no common outcomes can occur innnways, then the first or second event can occur inm+nm+nways
https://openstax.org/books/college-algebra-2e/pages/9-key-terms
annuity : an investment in which the purchaser makes a sequence of periodic, equal payments
https://openstax.org/books/college-algebra-2e/pages/9-key-terms
arithmetic sequence : a sequence in which the difference between any two consecutive terms is a constant
https://openstax.org/books/college-algebra-2e/pages/9-key-terms
arithmetic series : the sum of the terms in an arithmetic sequence
https://openstax.org/books/college-algebra-2e/pages/9-key-terms
binomial coefficient : the number of ways to chooserobjects fromnobjects where order does not matter; equivalent toC(n,r),C(n,r),denoted(nr)(nr)
https://openstax.org/books/college-algebra-2e/pages/9-key-terms
binomial expansion : the result of expanding(x+y)n(x+y)nby multiplying
https://openstax.org/books/college-algebra-2e/pages/9-key-terms
Binomial Theorem : a formula that can be used to expand any binomial
https://openstax.org/books/college-algebra-2e/pages/9-key-terms
combination : a selection of objects in which order does not matter
https://openstax.org/books/college-algebra-2e/pages/9-key-terms
common difference : the difference between any two consecutive terms in an arithmetic sequence
https://openstax.org/books/college-algebra-2e/pages/9-key-terms
common ratio : the ratio between any two consecutive terms in a geometric sequence
https://openstax.org/books/college-algebra-2e/pages/9-key-terms
complement of an event : the set of outcomes in the sample space that are not in the eventEE
https://openstax.org/books/college-algebra-2e/pages/9-key-terms
diverge : a series is said to diverge if the sum is not a real number
https://openstax.org/books/college-algebra-2e/pages/9-key-terms
event : any subset of a sample space
https://openstax.org/books/college-algebra-2e/pages/9-key-terms
experiment : an activity with an observable result
https://openstax.org/books/college-algebra-2e/pages/9-key-terms
explicit formula : a formula that defines each term of a sequence in terms of its position in the sequence
https://openstax.org/books/college-algebra-2e/pages/9-key-terms
finite sequence : a function whose domain consists of a finite subset of the positive integers{1,2,…n}{1,2,…n}for some positive integernn
https://openstax.org/books/college-algebra-2e/pages/9-key-terms
Fundamental Counting Principle : if one event can occur inmmways and a second event can occur innnways after the first event has occurred, then the two events can occur inm×nm×nways; also known as the Multiplication Principle
https://openstax.org/books/college-algebra-2e/pages/9-key-terms
geometric sequence : a sequence in which the ratio of a term to a previous term is a constant
https://openstax.org/books/college-algebra-2e/pages/9-key-terms
geometric series : the sum of the terms in a geometric sequence
https://openstax.org/books/college-algebra-2e/pages/9-key-terms
index of summation : in summation notation, the variable used in the explicit formula for the terms of a series and written below the sigma with the lower limit of summation
https://openstax.org/books/college-algebra-2e/pages/9-key-terms
infinite sequence : a function whose domain is the set of positive integers
https://openstax.org/books/college-algebra-2e/pages/9-key-terms
infinite series : the sum of the terms in an infinite sequence
https://openstax.org/books/college-algebra-2e/pages/9-key-terms
lower limit of summation : the number used in the explicit formula to find the first term in a series
https://openstax.org/books/college-algebra-2e/pages/9-key-terms
Multiplication Principle : if one event can occur inmmways and a second event can occur innnways after the first event has occurred, then the two events can occur inm×nm×nways; also known as the Fundamental Counting Principle
https://openstax.org/books/college-algebra-2e/pages/9-key-terms
mutually exclusive events : events that have no outcomes in common
https://openstax.org/books/college-algebra-2e/pages/9-key-terms
n factorial : the product of all the positive integers from 1 tonn
https://openstax.org/books/college-algebra-2e/pages/9-key-terms
nth partial sum : the sum of the firstnnterms of a sequence
https://openstax.org/books/college-algebra-2e/pages/9-key-terms
nth term of a sequence : a formula for the general term of a sequence
https://openstax.org/books/college-algebra-2e/pages/9-key-terms
outcomes : the possible results of an experiment
https://openstax.org/books/college-algebra-2e/pages/9-key-terms
permutation : a selection of objects in which order matters
https://openstax.org/books/college-algebra-2e/pages/9-key-terms
probability : a number from 0 to 1 indicating the likelihood of an event
https://openstax.org/books/college-algebra-2e/pages/9-key-terms
probability model : a mathematical description of an experiment listing all possible outcomes and their associated probabilities
https://openstax.org/books/college-algebra-2e/pages/9-key-terms
recursive formula : a formula that defines each term of a sequence using previous term(s)
https://openstax.org/books/college-algebra-2e/pages/9-key-terms
sample space : the set of all possible outcomes of an experiment
https://openstax.org/books/college-algebra-2e/pages/9-key-terms
sequence : a function whose domain is a subset of the positive integers
https://openstax.org/books/college-algebra-2e/pages/9-key-terms
series : the sum of the terms in a sequence
https://openstax.org/books/college-algebra-2e/pages/9-key-terms
summation notation : a notation for series using the Greek letter sigma; it includes an explicit formula and specifies the first and last terms in the series
https://openstax.org/books/college-algebra-2e/pages/9-key-terms
term : a number in a sequence
https://openstax.org/books/college-algebra-2e/pages/9-key-terms
union of two events : the event that occurs if either or both events occur
https://openstax.org/books/college-algebra-2e/pages/9-key-terms
upper limit of summation : the number used in the explicit formula to find the last term in a series
https://openstax.org/books/college-algebra-2e/pages/9-key-terms
The number of subsets of a finite setAAis equal to 2 raised to the power ofn(A)n(A), wheren(A)n(A)is the number of elements in setAA: Number of Subsets of SetA=2n(A)A=2n(A).
https://openstax.org/books/contemporary-mathematics/pages/1-formula-review
The cardinality ofAAunionB:n(A∪B)=n(A)+n(B)−n(A∩B)B:n(A∪B)=n(A)+n(B)−n(A∩B)
https://openstax.org/books/contemporary-mathematics/pages/1-formula-review
Identify a set as being a well-defined collection of objects and differentiate between collections that are not well-defined and collections that are sets.
https://openstax.org/books/contemporary-mathematics/pages/1-key-concepts
Represent sets using both the roster or listing method and set builder notation which includes a description of the members of a set.
https://openstax.org/books/contemporary-mathematics/pages/1-key-concepts
In set theory, the following symbols are universally used:ℕ - The set of natural numbers, which is the set of all positive counting numbers.ℕ={1,2,3,...}ℕ={1,2,3,...}ℤ - The set of integers, which is the set of all the positive and negative counting numbers and the number zero.ℤ={...,−2,−1,0,1,2,...}ℤ={...
https://openstax.org/books/contemporary-mathematics/pages/1-key-concepts
Distinguish between finite sets, infinite sets, and the empty set to determine the size or cardinality of a set.
https://openstax.org/books/contemporary-mathematics/pages/1-key-concepts