Sequences and Series Flashcards
What is an arithmetic series
Where the numbers go up by addition or subtraction
What is a geometric series?
Where the number go up by multiplication or division
What is the equation for finding the nth term of an arithmetic series?
Un = a + (n-1)d
a = first term
d = common difference
What is the equation for finding the sun of an arithmetic series?
Sn = 1/2 n(a + l)
Or
Sn = 1/2 n(2a + (n-1)d)
What is the equation for finding the nth term of a geometric series?
Un = ar^(n-1)
a = first term
r = common ratio
How do you calculate the common ratio?
n / n-1
e.g 2nd/1st
What is the equation for the sum of a geometric series?
Sn = a(l-r^n) / (l-r)
What is the equation for the sun to infinity?
S8 = a / (1-r)
What is the formula for sigma notation?
Weird E with a number above and r= number below. These numbers are the first and last.
This goes next to the formula being used.
