Question

the 1st term of an arthmatic sequence is 2 and the nth term is -16 and the sum of 1st n terms is -49. find the value of n

Answer 1

It is given to you that the first term of the A.P is 2 = a (first term)

Also, given that nth term ( \(a_n \) ) = -16

and Sum of first n terms ( \( S_n\) ) = -49

Use the following formula to find the value of n :

\(\boxed{\large \mathsf{ S_n = \cfrac{n}{2} (a + a_n)}}\)

Answer 2

Plug-in the given values and find the value of n.