Date | November 2020 | Marks available | 5 | Reference code | 20N.1.AHL.TZ0.H_5 |
Level | Additional Higher Level | Paper | Paper 1 (without calculator) | Time zone | Time zone 0 |
Command term | Express and Find | Question number | H_5 | Adapted from | N/A |
Question
The first term in an arithmetic sequence is 4 and the fifth term is log2 625.
Find the common difference of the sequence, expressing your answer in the form log2 p, where p∈ℚ.
Markscheme
* This question is from an exam for a previous syllabus, and may contain minor differences in marking or structure.
u5=4+4d=log2 625 (A1)
4d=log2 625-4
attempt to write an integer (eg 4 or 1) in terms of log2 M1
4d=log2 625-log2 16
attempt to combine two logs into one M1
4d=log2 (62516)
d=14log2 (62516)
attempt to use power rule for logs M1
d=log2 (62516)14
d=log2 (52) A1
[5 marks]
Note: Award method marks in any order.