MATHEMATICS

RG.NO. 13386008

THANSEELA.N

ST. THOMAS TRAINING COLLEGE.

ARITHMETIC SEQUENCES

NUMBER SEQUENCE

A collection of numbers written in order as the first, second, third and so on…

Number sequence from real life

The petals of sunflowerHoles of a honey combGraiz on a maize cobThe length of a the rungs of a ladder .

Examples…

1.

2

3. 100, 200, 300,…4. 1,1,2,3,5,8,13,….

ARITHMETIC SEQUENCE

A sequence which starts with any number(a) and proceed by addition of one number (d) again and again give arithmetic sequence (arithmetic progression)

Examples… 1, 2, 3, 4, 5…. ½ , 1 , 3/2 , 2 … 1 ,4, 7,10, 13… In general a, a+d, a+2d …..

Xn = an+b is general form of an A.P

nth term of an A.P

a+(n-1)dWhere a first term,d common difference

Sum of natural numbers

n(n+1)/2

Sum of odd numbers

n*n

Sum of A.P

S= n/2[2a+(n-1)d]