Question

check if the sequence whose nth term is 2 - 5n is an A.P. If so, Find the first term and the common difference ​

Answer 1

Explanation:

AP : 2-5n

a1 = 2- 5×1 = 2-5 = -3

a2 = 2- 5× 2 = 2-10 = -8

a3 = 2-5×3 = 2-15 = -13

d = a2-a1 = -8 - (-3)= -8 + 3 = -5

a3-a2= -13 - (-8) = -13 + 8 = -5

As they have a common difference so they are in AP.

First term = -3 and common difference = -5