Class 11 Maths Sequences Series Sequence & Series

Sequence & Series

A sequence is an ordered collection of objects in which repetitions are allowed. E.g.: 1,1,2,2,2,3,3,4,6,7,8,8,9,

Sequences, following specific patterns are called progressions. E.g. If you put 10Rs in piggy bank daily then the amount in money in you piggy bank on next few days will be 10,20,30,40,50….. etc.

There is a pattern in this sequence, the difference between any two consecutive numbers is 10, and thus this sequence is Progression.  This type of progression is called Arithmetic Progression.

If you deposit Rs 500 in a bank & bank agrees to double your money every year. Then amount of money in your account over next few years will be 500, 1000, 2000, 4000, 8000 etc

There is a pattern in this sequence too, here if you divide any two consecutive numbers you will get same value.  1000/500 = 2000/1000 =2 & thus this sequence is also Progression. This type of progression is called Geometric Progression

A series is the sum of the terms of a sequence. E.g. for a sequence 1,2,3,3,4 , Series is 1+2+3+3+4.

.