Q9 of 202 Page 10

Write the sum of first n even natural numbers.

First n even Natural numbers are 2, 4, 6,……, 2n

This forms an A.P where

a= 2

l= 2n where l is last term of the A.P

S_n =

Write the nth term of an A.P. the sum of whose n terms is S_n.

Write the sum of first n odd natural numbers.

1f the sum of n terms of an A.P. is S_n = 3n² + 5n. Write its common difference.

Write the expression for the common difference of an A.P. whose first term is a and nth term is b.