There was one example in my school work today that didn't make sense.

You need to figure out the formula for the following pattern

-1, 5, -9, 13, -7

The provided solution is:

Odd numbers: -1^n

Even numbers: 4n -3

They don't show how they got there at all.

As you could probably see the odd number solution does not work.

But I can't figure out the actual formula.

Could someone please help me with this?

Guest Mar 5, 2018

edited by
Guest
Mar 5, 2018

#1**0 **

The formula is a combination of both ie (-1)^{n} (4n-3) where n = 1,2,3,....

you see the (-1)^{n }is just the mathematical way of putting a minus sign in front of a number.

odd powers give a minus and even powers give a plus eg (-1)^{3 }= -1 , (-1)^{6 }= 1

and of course the 4n-3 gives you 1,5,9,......

Guest Mar 6, 2018