Question

In the geometric progression –3, 12, −48… what term is 3,072?

Answer 1

hello : A6 =3072

Explanation:

note : the nth term is : An =A1 × r^(n-1)

A1 = - 3 and r = 12/-3 =- 48/12 = - 4

An =(-3) × (-4)^(n-1)

you have : An = 3072 calculate : n

(-3) × (-4)^(n-1) = 3072

(-4)^(n-1) = - 1024

but : - 1024 = ( - 4 )^5

so ; (-4)^(n-1) = ( - 4 )^5

n - 1 = 5

n = 6 A6 =3072

Answer 2

The 6. term

Explanation:

Make a table for

y = - 3·(-4)^(x - 1)