A student is attempting to find a formula for the sequence below. Which statement best applies to the sample mathematical work?

2 answers:

monitta3 years ago

7 0

The sample is a geometri sequencethe ratio = -9 / 3 = -3= 27 / -9 = -3so it is clearly a geometric sequencethen the formula of a geometric sequence:
an = ar^(n-1)where an is the n terma is the initial termr is the rationn is the number of term
an = 3(-3)^(n-1)is the answer

Sunny_sXe [5.5K]3 years ago

4 0

Answer:

Answer : B

Step-by-step explanation:

Our sequence is 3,-9,27,........This is a geometric sequence. whose first terms is 3 which is generally denoted by "a" .The common ratio is find out by taking the ration of second term to the first term. In this case it would be ,

$r=\frac{-9}{3}$

Hence r=-3

Now the formula for the nth term of any geometric sequence is given as

$a_{n}$ = $ar^{n-1}$

Hence we now replace the value of a and r in this to find the right answer which is

$a_{n} = 3(-3)^{n-1}$

Hence B option is correct as the first term is not taken into the account in this answer.

You might be interested in

Explain how the net of rectangular prism can help you find the surface area or the prism?

Aleksandr-060686 [28]

A 3d cardboard box has 6 sides, each of which are rectangles. If you unfold the 3D box, and flatten it out, then you'll be left with 6 rectangles such as what you see in the attachment below. This is one way to unfold the box. This flattened drawing is the net of the 3D rectangular prism. You can think of it as wrapping paper that covers the exterior of the box. There are no gaps or overlapping portions. If you can find the area of each piece of the net, and add up those pieces, that gets you the total area of the net. This is the exactly the surface area of the box.

In the drawing below, I've marked the sides as: top, bottom, left, right, front, back. This way you can see how the 3D box unfolds and how the sides correspond to one another. Other net configurations are possible.