Question

nth terms

Answer 1

Find an equation for the nth term of the sequence. -4, -16, -64, -256, ...

Answer 2

So basically what you have here is a set of points where:

(n,r) = {(1,-4),(2, -16),(3,-64),(4,-256),...}

Answer 3

So now what you have to do is find a relationship between n and r and then write it in the form of an equation.

Answer 4

Whatever the relationship between n and r it has to be consistent for each (n,r) pair.

Answer 5

Since you already have answer choices, what you can do is plug the points in to see which choice agrees with the points. Start with n = 1

Answer 6

hey see its a gp series ....with firest term = -4 and the common ration is = 4

Answer 7

so...now directly apply the formula...to find the nth term

Answer 8

Hang on, let me double check your work @lovelyharmonics

Answer 9

I assumed that you knew how to multiply expressions.

Answer 10

Can you show the work you did to get each answer you got?

Answer 11

I'm more comfortable when students show their work.

Answer 12

To demonstrate that they know what they are doing.

Answer 13

Please show the work you did for a, b, c, and d

Answer 14

You didn't show how you got the -4 for example

Answer 15

By showing work, I mean post the complete computational steps you performed to arrive at each answer for choices a,b,c,d

Answer 16

I see what you did wrong now. For d:

an = -4 • 4(n - 1)
= -4 • 4(1 - 1)
= -4 • 4(0)
= -4 • 0
= 0

Answer 17

@lovelyharmonics, when posting answer choices, you cannot neglect parentheses.

Answer 18

Parentheses matter

Answer 19

@hero @lovelyharmonics u know what the options are wrongly given....

Answer 20

I agree with @rishavraj

Answer 21

None of the answer choices seem to be correct. This is why from the beginning I was trying to guide the user through a process that would yield the proper equation

Answer 22

@rishavraj do not give the answer under any circumstances.

Answer 23

Just because you know what it should be, that doesn't mean tell what it is. Giving answers is giving answers no matter how you look at it.

Answer 24

@hero dont worry i am not gonna give the answer i am only mending the options

Answer 25

But I agree though. She apparently is not familiar with using caret symbols to represent exponents.