Date | November 2016 | Marks available | 2 | Reference code | 16N.1.SL.TZ0.S_9 |
Level | Standard Level | Paper | Paper 1 | Time zone | Time zone 0 |
Command term | Show that | Question number | S_9 | Adapted from | N/A |
Question
The first two terms of an infinite geometric sequence, in order, are
, where .
The first three terms of an arithmetic sequence, in order, are
, where .
Let be the sum of the first 12 terms of the arithmetic sequence.
Find .
Show that the sum of the infinite sequence is .
Find , giving your answer as an integer.
Show that .
Given that is equal to half the sum of the infinite geometric sequence, find , giving your answer in the form , where .
Markscheme
* This question is from an exam for a previous syllabus, and may contain minor differences in marking or structure.
evidence of dividing terms (in any order) (M1)
eg
A1 N2
[2 marks]
correct substitution (A1)
eg
correct working A1
eg
AG N0
[2 marks]
evidence of subtracting two terms (in any order) (M1)
eg
correct application of the properties of logs (A1)
eg
correct working (A1)
eg
A1 N3
[4 marks]
correct substitution into the formula for the sum of an arithmetic sequence (A1)
eg
correct working A1
eg
AG N0
[2 marks]
correct equation (A1)
eg
correct working (A1)
eg
(accept ) A1 N2
[3 marks]