What is the tenth term of the given geometric sequence: -1, 4, - 16, 64, ... ?

А: 262,144
B: 4,194,304
C: -65,536
D: -1,048,576

Respuesta :

Answer:

262144

Step-by-step explanation:

Geometric sequence : -1 , 4 , -16 , 64 .....

Ratio = 2nd term ÷ 1st term = 4 ÷ (-1)= -4

a =  first term = -1

r = -4

Each term is obtained by multiplying the previous term by (-4)

nth term = [tex]ar^{n-1}[/tex]

10th term = [tex](-1) * (-4)^{9}= -1 * (-262144) = 262144[/tex]