Sequences and series help maths

Help! Is there some kinda method of working out what u50 is. I know this is a periodic sequence with period 2. But idk how in an exam I would be able to quickly work u50 because it’s only a mark

Reply 1

Notnek

Original post by Alevelhelp.1

Help! Is there some kinda method of working out what u50 is. I know this is a periodic sequence with period 2. But idk how in an exam I would be able to quickly work u50 because it’s only a mark

Are you asking how to work out the 50th term for a sequence that repeats every 2 terms?

E.g. 1, 2, 1, 2, 1, 2, …

What will the 50th term be?

Or are you asking something else?

Reply 2

Alevelhelp.1

Original post by Notnek

Are you asking how to work out the 50th term for a sequence that repeats every 2 terms?

E.g. 1, 2, 1, 2, 1, 2, …

What will the 50th term be?

Or are you asking something else?

Yes I’m asking this

Reply 3

old_engineer

Original post by Alevelhelp.1

Yes I’m asking this

You could observe that all the odd terms in the sequence are equal to 1. And as for the even terms...

Reply 4

Notnek

Original post by Alevelhelp.1

Yes I’m asking this

If your periodic sequence was this:

1, 2, 1, 2, 1, 2, 1, 2, ...

The 2nd term is 2. The 4th term is 2. The 6th term is 2.

See the pattern? So what's the 50th term?