Lami13
Badges: 3
Rep:
?
#1
Report Thread starter 11 months ago
#1
Anyone can help me with this problem.Consider the sequence 1,1,3,(1/3),9,(1/9),27,(1/27),81,(1/81),.......Show that the sum of the first 2n terms of the sequence is 1/2[2-(3^n)-(3^(n-1)].
0
reply
mqb2766
Badges: 18
Rep:
?
#2
Report 11 months ago
#2
(Original post by Lami13)
Anyone can help me with this problem.Consider the sequence 1,1,3,(1/3),9,(1/9),27,(1/27),81,(1/81),.......Show that the sum of the first 2n terms of the sequence is 1/2[2-(3^n)-(3^(n-1)].
What do you notice about the sequence(s)?

The hint is in my question.
0
reply
Lami13
Badges: 3
Rep:
?
#3
Report Thread starter 11 months ago
#3
(Original post by mqb2766)
What do you notice about the sequence(s)?

The hint is in my question.
I still don’t know how to prove it.
0
reply
mqb2766
Badges: 18
Rep:
?
#4
Report 11 months ago
#4
(Original post by Lami13)
I still don’t know how to prove it.
What do you notice about the sequence(s)?

The aim is to help you do the question, not do it for you.
0
reply
Matureb
Badges: 18
Rep:
?
#5
Report 11 months ago
#5
Split the 2n sequence into two sequences of length n
0
reply
Lami13
Badges: 3
Rep:
?
#6
Report Thread starter 11 months ago
#6
(Original post by Matureb)
Split the 2n sequence into two sequences of length n
Hahaha got it. Thanks 😊
0
reply
Lami13
Badges: 3
Rep:
?
#7
Report Thread starter 11 months ago
#7
Name:  image.jpg
Views: 18
Size:  99.7 KB Anyone may help me solve these 2 questions
0
reply
mqb2766
Badges: 18
Rep:
?
#8
Report 11 months ago
#8
(Original post by Lami13)
Name:  image.jpg
Views: 18
Size:  99.7 KB Anyone may help me solve these 2 questions
Looks like you need to represent the circles as a sequence (geometric progression?). Try working out the intiial value and the ratio for the radius (circumference) / area? I suppose looking at the side length : radius for the initial triangle would be good, then thinking about how the triangle gets divided up at each stage?

The snowflake is well described online. What have you done / what problems are you having?
Last edited by mqb2766; 11 months ago
1
reply
X

Quick Reply

Attached files
Write a reply...
Reply
new posts
Back
to top
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise

Current uni students - are you thinking of dropping out of university?

Yes, I'm seriously considering dropping out (185)
14.14%
I'm not sure (59)
4.51%
No, I'm going to stick it out for now (383)
29.28%
I have already dropped out (37)
2.83%
I'm not a current university student (644)
49.24%

Watched Threads

View All