Question

What is the equation of the sequence 2 -4 8 -10 12

Answer 1

I see that is it subtracting 6 then adding 12 then subtracting 18 and so on and the equation for that is 6(-x)^x/(x^x-1) but I dont know where to go from there or if im even on the right track

Answer 2

you sure you got the sequence correct?

Answer 3

positive

Answer 4

4 8 16 20 24
4 8 4 4

i keep getting an oddball in there

Answer 5

we can construct an equation that will hit all these points; but theres no way to say that its the "correct" one

Answer 6

how so?

Answer 7

form a system of 5 equations in 5 unknowns; and use a matrix and a computer to sort out the details :)

Answer 8

i dont know what that is lol

Answer 9

rref{{1,1,1,1,1,2},{2^5,2^4,2^3,2^2,2, -4},{3^5,3^4,3^3,3^2,3, 8},{4^5,4^4,4^3,4^2,4, -10},{5^5,5^4,5^3,5^2,5 12}}

http://www.wolframalpha.com/input/?i=rref%7B%7B1%2C1%2C1%2C1%2C1%2C2%7D%2C%7B2%5E5%2C2%5E4%2C2%5E3%2C2%5E2%2C2%2C+-4%7D%2C%7B3%5E5%2C3%5E4%2C3%5E3%2C3%5E2%2C3%2C+8%7D%2C%7B4%5E5%2C4%5E4%2C4%5E3%2C4%5E2%2C4%2C+-10%7D%2C%7B5%5E5%2C5%5E4%2C5%5E3%2C5%5E2%2C5%2C+12%7D%7D

Answer 10

the problem is that just creates a curve that hits the given points and doesnt really make the back and forth pattern

Answer 11

To be honest I dont even know what im looking at here

Answer 12

thats ok, it was just an idea. its not the answer they are loooking for by any means

Answer 13

I see its a matrix with the answers of the first three limes being the same as the first three numbers in the sequence

Answer 14

http://www.wolframalpha.com/input/?i=%7B+2%2C+-4%2C+8%2C+-10%2C+12%2C+...%7D

when i try to get the wolf to see a pattern, it cant even do it

Answer 15

as is, i dont think you can define a sequence from these numbers; unless youre missing something from the list ... but you say you isnt

Answer 16

i dont see a ... after it, so is it asking just for these numbers?

Answer 17

Im pretty sure it keep going...

Answer 18

I copied it of the teachers board so maybe I messed it up or they did if its impossible to do

Answer 19

if there is a pattern, then i dont see enough terms to make it definitive

Answer 20

good luck with it tho :)

Answer 21

yea thanks for trying to help