To find the value of f(4), we can use the given recursive formula:
f(n+1) = -2f(n)
Starting with f(1) = 160, we can calculate the subsequent values:
f(2) = -2f(1) = -2 * 160 = -320
f(3) = -2f(2) = -2 * (-320) = 640
f(4) = -2f(3) = -2 * 640 = -1280
Therefore, f(4) is -1280.