Question

Write a rule for the nth term of the geometric sequence given the info.

a1=4, a2=12

Answer 1

We need more info. It can be either an AP or GP.

Answer 2

whats ap of gp mean?

Answer 3

AP mean arithmetic progression.

GP mean Geometric progression.

Answer 4

i know the question states its a geometric progression....

Answer 5

a2/a1 = 3, so 4*3^(n-1).

Answer 6

? idk what ur saying...

Answer 7

a2 divided by a1????

Answer 8

pleasde help im dying.

Answer 9

since its geometric, try to figure out how to get from 4 to 12 geometrically (multiply by something)

Answer 10

so times 3

Answer 11

yeah. using the formula An = A1 * r ^ (n-1).
we just found out that r is 3, and you already know A1 is 4.
The answer given by primeralph was correct, when you plug in all of the values you get that An = 4*3^(n-1)

Answer 12

oohk so thats the answer?

Answer 13

How would u do this: Write the series -5+5+15+25+35 using summation notation?

Answer 14

@ayubie

Answer 15

OHH. okay haha give me just a minute.