Find the 11 th term of the geometric sequence 64, -32, 16, -8, …

Answer 1

common ratio, r, = -1/2

an = a1(r)^(n-1)

a11 = (64)(-1/2)^10 = (2^6)/2^10 = 2^-4 = 1/16 = the 11th term

64,-32,16,-8,4,-2,1,-1/2, 1/4, -1/8, 1/16