Question

Find the fifth term of an=(-1)^n/2n-1

a.-1/7 b.-1/9 c.1/9 d.1/7

Answer 1

B

Explanation:

right on edge 2021

Answer 2

b) -1/9

Explanation:

Given

`a_(n) = ((-1)^(n) )/(2n-1)`

First term

`a_(1) = ((-1)^(1) )/(2(1)-1) = -1`

second term

`a_(2) = ((-1)^(2) )/(2(2)-1) = (1)/(3)`

Third term

`a_(3) = ((-1)^(3) )/(2(3)-1) = (-1)/(5)`

Fourth term

`a_(4) = ((-1)^(4) )/(2(4)-1) = (1)/(7)`

Fifth term

`a_(5) = ((-1)^(5) )/(2(5)-1) = (-1)/(9)`