Question

If a1=3 and an=-2an-1 then find the whole value of a 5

Answer 1

a₅ = 48

Explanation:

using the recursive rule
`a_(n)` = - 2
`a_(n-1)` and a₁ = 3 , then

a₂ = - 2a₁ = - 2(3) = - 6

a₃ = - 2a₂ = - 2(- 6) = 12

a₄ = - 2a₃ = - 2(12) = - 24

a₅ = - 2a₄ = - 2(- 24) = 48