how do i solve this? Question
Two terms of a geometric sequence are a3=12 and a5=48.

What is the value of a17?

Respuesta :

Answer:

a₁₇ = 196608

Step-by-step explanation:

The nth term of a geometric sequence is

[tex]a_{n}[/tex] = a₁ [tex]r^{n-1}[/tex]

where a₁ is the first term and r the common ratio

Given a₃ = 12 and a₅ = 48 , then

a₁ r² = 12 → (1)

a₁ [tex]r^{4}[/tex] = 48 → (2)

Divide (2) by (1)

[tex]\frac{a_{1}r^{4} }{a_{1}r^{2} }[/tex] = [tex]\frac{48}{12}[/tex] , that is

r² = 4 ( take square root of both sides )

r = 2

substitute r = 2 into (1)

a₁ 2² = 12

4a₁ = 12 ( divide both sides by 4 )

a₁ = 3

Then

a₁₇ = 3 × [tex]2^{16}[/tex] = 3 × 65336 = 196608

Answer:

a₁₇ = 196608

Step-by-step explanation:

The nth term of a geometric sequence is = a₁ where a₁ is the first term and r the common ratio.

Given a₃ = 12 and a₅ = 48 , then

a₁ r² = 12 → (1)

a₁  = 48 → (2)

Divide (2) by (1)

=  , that is

r² = 4 ( take square root of both sides )

r = 2

substitute r = 2 into (1)

a₁ 2² = 12

4a₁ = 12 ( divide both sides by 4 )

a₁ = 3

Then

a₁₇ = 3 ×  = 3 × 65336 = 196608

Hence, the correct answer is a₁₇ = 196608