Question

Find the third term of the geometric sequence when a1=1/4 and r=−2

A. -4
B. 12
C. 1
D. −12

Answer 1

Answer:

1 is the third term.

Step-by-step explanation:

Geometric sequences have a common ratio.  This means a term divided by previous term is the same no matter the choosing of term.

So for example:

$\frac{a_{n}}{a_{n-1}}=\frac{a_{n-1}}{a_{n-2}}=\cdots=\frac{a_4}{a_3}=\frac{a_3}{a_2}=\frac{a_2}{a_1}$

So anyways geometric sequences means you are just multiply the common ratio over and over to generate the next term.

So, the first term is 1/4.

The second term is (-2)(1/4)=-1/2.

The third term is (-2)(-1/2)=1.