Question

87th term of 12,0,-12

Answer 1

`a_(87) = -1020`

Explanation:

Given:

The given AP is.

12,0,-12,......

`n=87`

The first term of an AP
`a=12`

Common difference
`d=0-12=-12`

We use the the formula for nth term of an AP.

`a_(n) = a+(n-1)d`

for 87th term

`a_(87) = 12+(87-1)(-12)`

`a_(87) = 12+(86)(-12)`

`a_(87) = 12+(-1032)`

`a_(87) = 12-1032`

`a_(87) = -1020`

Therefore, The 87th term of given series is -1020.