Question

Find the indicated terms in the following sequences whose nth term is:

a_n = 5n – 4; a₁₂ and a₁₅

Answer 1

Here, we are given the n^th term for various sequences. We need to find the indicated terms of the A.P.

`a_n = 5n - 4`

We need to find `a_12` and `a_15`

Now to find `a_12` term we use n = 12 we get

`a_12 = 5(12) - 4`

= 60 - 4

= 56

Also to find `a_15` term we use n = 15, we get

`a_15 = 5(15) - 4`

= 75 - 4

= 71

Thus `a_12 = 56` and `a_15 = 71`