the sequence shown below is defined using a recursion formula. Write the first four terms of the sequence.
a[1]=13 and a[n]=a[n-1]+8 for n≥2
a[1]=13 and a[n]=a[n-1]+8 for n≥2
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All that is saying is that a[n]=the term before it plus 8. It is easy to rewrite these in standard notation, but I'm not even going to bother since you just need the first four terms.
I'm going to go through algebraically how to get a[2] and then just say the rest.
a[n]=a[n-1]+8,
So,
a[2]=a[2-1]+8
a[2]=a[1]+8
We know that a[1]=13, so
a[2]=13+8=21
There you go! As you can see all we did was add 8 to the last term. So the first two terms are:
13,21
Then just add 8 to get the next one, and another 8 for the 4th. And that's it.
13,21,29,37...
I'm not sure where they were going with that n≥2...
I'm going to go through algebraically how to get a[2] and then just say the rest.
a[n]=a[n-1]+8,
So,
a[2]=a[2-1]+8
a[2]=a[1]+8
We know that a[1]=13, so
a[2]=13+8=21
There you go! As you can see all we did was add 8 to the last term. So the first two terms are:
13,21
Then just add 8 to get the next one, and another 8 for the 4th. And that's it.
13,21,29,37...
I'm not sure where they were going with that n≥2...