Question

If the 3rd and the 9th terms of an AP are 4 and -8 respectively, which term of this AP is
zero?
please answer the question​

Answer 1

Answer:

5th term of AP will be zero.

Answer 2

Answer:

we have , 3rd term of an ap=4

9th term of an ap=-8

a+2d=4......... (1)

a+8d= -8........ (2)

now add (1) &(2),

6d= -12

d= -12/6

d= -2........... put the value of d= -2 in (1)

now, a+2d=4

a+2(-2) =4

a-4=4

a=4+4

a=8

now , we have given the value of an=0

an=a+(n-1) d

0=8+(n-1) -2

0-8=(n-1) -2

-8/-2=(n-1)

4=(n-1)

n-1=4

n=4+1

n=5