A sequence (an) is given by the formula an 10-3n, Prove that it is an

1.	A sequence (an) is given by the formula an 10-3n, Prove that it is an A.P
Answer» An = 10 - 3n Putting value of n, Let n = 1 , Then, A1 = 10 - 3 1 A1 = 7 For n = 2, A2 = 10 - 3 2 A2 = 10 - 6 = 4 For n = 3 , A3 = 10 - 3 * 3 A3 = 10 - 9 = 1 Now, A2 - A1 = 4 - 7 = - 3 = d A3 - A2 = 1 - 4 = - 3 = d Since, Difference is common. So, Common difference is same. Hence, The given sequence is in A. P. hmmm

A sequence (an) is given by the formula an 10-3n, Prove that it is an A.P

Answer»

An = 10 - 3n

Putting value of n,

Let n = 1 ,

Then,

A1 = 10 - 3 *1

A1 = 7

For n = 2,

A2 = 10 - 3 *2

A2 = 10 - 6 = 4

For n = 3 ,

A3 = 10 - 3 * 3

A3 = 10 - 9 = 1

Now,

A2 - A1 = 4 - 7 = - 3 = d

A3 - A2 = 1 - 4 = - 3 = d

Since, Difference is common.

So, Common difference is same.

Hence, The given sequence is in A. P.

hmmm