00:01
Hi, on this problem we are given an arithmetic sequence of 5, 3, 1, and negative 1.
00:12
And they would like for us to write both the recursive and explicit formula for this arithmetic sequence.
00:18
So since we know it's arithmetic, we're gonna find the common difference.
00:22
So we're gonna take the second number minus the first number, so 3 minus 5 is negative 2.
00:28
So we know the common difference is a negative 2.
00:30
So first let's write the recursive formula.
00:33
So recursive is you tell everyone what the first number is.
00:40
So in this case, the first number is five.
00:43
And then we've got to tell them the rule.
00:45
So it says for any number of the sequence, you take the previous number, and you're going to subtract two.
00:51
And this is for when your n is greater than or equal to two...