Question

term.
9. If the 3rd and the 9th terms of an AP are 4 and – 8 respectively, which term of the
zero?​

Answer 1

Answer:

5th term

Step-by-step explanation:

3rd term of AP= 4

⇒ a + 2d = 4                       _(i)

9th term of AP = -8

⇒ a + 8d = -8                     _(ii)

From eq. (i) and eq.(ii), we get

d= -2   and a= 8

nth term of AP = 0

⇒ a+ (n-1)d = 0

⇒ 8 + (n-1)(-2) = 0

⇒ 8 -2n +2 =0

⇒  n =$\frac{-10}{-2}$

⇒ n= 5

Hence, the 5th term of the AP is zero.

Hope it is helpful.