00:01
We're being asked to find the first five terms in the given recursively defined sequence.
00:05
Well, we know that a sub 1 is equal to a, so the first term is a.
00:09
Now, to find a sub 2, we're going to substitute 2 in place of n in our formula.
00:14
So we're going to have a sub, while 2 minus 1 is 1 plus d.
00:18
And we know that a sub 1 is equal to a.
00:20
So a sub 2 will be equal to a plus d.
00:24
Now, to find the third term in the sequence, we substitute 3 in place of that in our formula.
00:28
So we'll have a sub 3 minus 1, which is 2, plus d.
00:33
Well, a sub 2, we just found to be a plus d.
00:36
So we're going to be left with a plus d plus d.
00:39
Well, d plus d is equal to 2d.
00:42
So the third term in the sequence will be a plus 2d.
00:46
Now, to find the fourth term in the sequence, we substitute four in place of n.
00:50
So we'll have a sub 4 minus 1, which is 3 plus d...