1.6 Series

[ PURE 1 ] 1) Arithmetic Sequence 2) Geometric Sequence 3) Sum to Infinity

What is an Arithmetic Sequence/Progression

Any sequence with a common difference (d) + or --

What is a Geometric Sequence/Progression

Any sequence with a common ratio (r) \* or ÷

What is “a”

First term

What is “T1”

a (First term)

What is “n”

n = no of term

What is the formula of Tn (nth term/last term) in an AP

Write the formula (AP)

What is the first step in solving an AP question

Convert any and every term into “a”, first term, and “d”, common difference

What is the formula of n (AP)

What is Sn

Sum of n terms

What is S1

T1 = a = first term

What is the formula of Sn in an AP

What is the formula

What is the formula of Tn in an GP

Write the formula

What is the first step in solving a GP question

Convert any and every term into “a”, first term, and “r”, common ratio

What is the formula of Sn in a GP

When r

What is the formula of Sn in a GP

When r>1

What is the sum to infinity

An infinite geometric sequence

What is the formula for sum to infinity

When

( -1 < r < 1 )