If f(1)=8f(1)=8 and f(n)=2f(n-1)f(n)=2f(n−1) then find the value of f(5)f(5).

Question

I don't know how to do it.

Answer 1

If you mean f(1) = 8 and f(n) = 2f(n-1), then f(n) = 2ⁿ⁺² and f(5) =2^7.

If this is not what you mean, you will need to clarify your notation.