Question

If f(1) =160 and f(n+1) = -2f(n), what is f(4)?

Answer 1

-1280.

Explanation:

f(n + 1) = -2 f(n):

As function of 1 = 160, function of 2 = -2 * 160 = -320.

function of 3 = -320 * -2 = 640 and

= function of 4 = 640 * -2 = -1280.