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Date	November 2019	Marks available	5	Reference code	19N.2.AHL.TZ0.H_1
Level	Additional Higher Level	Paper	Paper 2	Time zone	Time zone 0
Command term	Find	Question number	H_1	Adapted from	N/A

Question

A geometric sequence has ${u_4} = - 70$ and ${u_7} = 8.75$ . Find the second term of the sequence.

Markscheme

${u_1}{r^3} = - 70$ , ${u_1}{r^6} = 8.75$ (M1)

${r^3} = \frac{{8.75}}{{ - 70}} = - 0.125$ (A1)

$\Rightarrow r = - 0.5$ (A1)

valid attempt to find ${u_2}$ (M1)

for example: ${u_1} = \frac{{ - 70}}{{ - 0.125}} = 560$

${u_2} = 560 \times - 0.5$

$= - 280$ A1

[5 marks]

Examiners report

[N/A]

Syllabus sections

Topic 1—Number and algebra » SL 1.3—Geometric sequences and series

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