Question

In an ap the first nth term is 3n^2/2 + 5n/2. Find its 23rd term .

Answer 1

Hi ,

an = 3n² / 2 + 5n/2 ----( 1 )

put n = 23 in equation ( 1 )

23 rd term = a23

a23 = [ 3 × ( 23 )² ] /2 + ( 5 × 23 ) /2

= ( 23 /2 ) [ 3 ×23 + 5 ]

= ( 23 / 2 ) × 74

= 23 × 37

= 851

Therefore ,

23rd term in given A P = a23 = 851

I hope this helps you.

:)