You are Here: Home

# nth term of a sequence.... Tweet

Maths and statistics discussion, revision, exam and homework help.

Announcements Posted on
1. nth term of a sequence....

Last edited by flown_muse; 18-03-2012 at 21:13.
2. Re: nth term of a sequence....
Set , and consider that . You should be able to make some progress from there (unless I've made a misunderstanding somewhere).
3. Re: nth term of a sequence....
Yeah that sounds right.
4. Re: nth term of a sequence....

Last edited by flown_muse; 18-03-2012 at 21:14.
5. Re: nth term of a sequence....
(Original post by flown_muse)
Okay, now I have:

and now I have an issue, because I can't find a value of k that can make both the top and the bottom equal to a power of 4.

I'm clearly doing something wrong
Write it as , and remember that , so you can expand the powers to get something easier.
6. Re: nth term of a sequence....
(Original post by flown_muse)
Okay, now I have:

and now I have an issue, because I can't find a value of k that can make both the top and the bottom equal to a power of 4.

I'm clearly doing something wrong
Expand the numerator and simplify.
7. Re: nth term of a sequence....

Last edited by flown_muse; 18-03-2012 at 21:15.
8. Re: nth term of a sequence....
(Original post by flown_muse)

etc.?
What's 3--1?

Apart from that yeah that's right. You can get rid of the 1 btw.
Last edited by f1mad; 18-03-2012 at 19:43.
9. Re: nth term of a sequence....
Yeah that's right. You can get rid of the 1 btw.
So, I have ended up with:

Therefore,
10. Re: nth term of a sequence....
(Original post by flown_muse)
So, I have ended up with:

Therefore,
Hang on, where did the last line come from?
11. Re: nth term of a sequence....
Hang on, where did the last line come from?
Because the question wants me to find An in terms of powers of 4, so I'm setting the power equal to 4.

(I think?)
12. Re: nth term of a sequence....
Oh. I never thought of that. I think you are right, because otherwise I end up with n=0 and the answer is just a number with no powers. Argh! Thanks
13. Re: nth term of a sequence....
(Original post by flown_muse)
Oh. I never thought of that. I think you are right, because otherwise I end up with n=0 and the answer is just a number with no powers. Argh! Thanks
Yeah you need to re-write it . In terms of 4^ something, since this would then imply powers of 4.