3.
If the second and the seventh terms of a geometric progression are 6 and 1458
respectively, find the first term.

Respuesta :

Answer:

steps below

Step-by-step explanation:

aₙ = a₁ * rⁿ⁻¹

a₁ * r²⁻¹ = 6

a₁ * r = 6   ... (1)

a₁ * r⁵ = 1458  ... (2)

(2)/(1) : r⁴ = 243      r = ±3 [tex]\sqrt[4]{3\\}[/tex]

if r = 3 [tex]\sqrt[4]{3\\}[/tex]

[tex]a_{1} = 6 / 3\sqrt[4]{3} \\a_{1} = \frac{2}{3} \sqrt[4]{27}[/tex]  

if r = -3 [tex]\sqrt[4]{3\\}[/tex]

[tex]a_{1} = -\frac{2}{3} \sqrt[4]{27}[/tex]