If f(1) = 160 and f(n+1)=-2f(n), what is f(4)? someone explain how to do this

f(1) = 160

f(2) is -2  times the previous value

f(2) = -2 *f(1) = -2 * 160 =  -320

f(3) = -2 * f(2) = -2 *(-320) = 640

f(4) = -2 * f(3) = -2 * 640 = -1280

f(4) = -1280

for ex: the reciprocal of 3/4 is 4/3. it is the opposite.

reciprocal definition:

a mathematical expression or function so related to another that their product is one; the quantity obtained by dividing the number one by a given quantity.