ARITHMETIC

PROGRESSIONS

• Finding the value of first term (a)

and common difference (d)

3) For following APs, write first term and the common difference:

i) 3, 1, -1, -3, …

Sol:

For given AP: 3, 1, -1, -3, …

First term(a) =

3

Common difference(d) =

1 – 3

= – 2

ii) -5, -1, 3, 7, …

Sol:

For given AP: -5, -1, 3, 7, …

First term(a) =

-5

Common difference(d) =

-1 – (-5)

= -1 + 5

= 4

Exercise 5.1 3(I,ii)

HOMEWORK

Sol:

First term(a) =

Common difference(d) =

iv) 0.6, 1.7, 2.8, 3.9, …

Sol:

For given AP: 0.6, 1.7, 2.8, 3.9, …

First term(a) =

0.6

Common difference(d) =

1.7 – 0.6

= 1.1

3) For following APs, write first term and the common difference:

Exercise 5.1 3(iii,iv)