Find the 10th term in the geometric sequence below.

2, - 4, 8, - 16, ...

a. - 1,024

b. 512

c. 1,024

d. 2,048

This is a geometric progression.

Because - 4/2 = 8/-4 = - 2. Hence common ratio r = - 2

The first term a = 2.

Tn for GP = ar^ (n-1)

10th term, = 2 * (-2) ^ (10 - 1) = 2 * (-2) ^9 = 2 * (-512) = - 1024

Tenth term = - 1024. Option a.