Question

Given the geometric sequence where a1 = 2 and r = √2 find a9 32 32√2 256 256√2

Answer 1

Answer: First option is correct.

Step-by-step explanation:

Since we have given that

There is a geometric sequence:

where a₁ = 2

r = √2

We need to find a₉:

As we know the formula for "nth term ":

$a_n=ar^{n-1}\\\\a_9=ar^{9-1}\\\\a_9=ar^8\\\\a_9=2\times (\sqrt{2})^8\\\\a_9=32$

Hence, First option is correct.

Answer 2

A9=a1*r^8

a9= 2*V2^8=2*2^4=2^5

⇒ a9 = 32