<p>Consider a geometric sequence, \(u_n\), with common ratio \(r\), where each term in the sequence is positive.<br>It is given that&nbsp;\(u_6 = 1.6 \times 10^5\) and \(u_8 = 6.4 \times 10^5\).</p>
<ol class="abc-list"><li data-list-item-id="item-1791188809490-umb815sn0" data-list-item-path="item-1791188809490-umb815sn0"><div class="list-item-paragraph"><p>Find the value of \(r\).</p><span class="inline-marks">[3]</span></div></li><li data-list-item-id="item-1791188810042-ar2150b4s" data-list-item-path="item-1791188810042-ar2150b4s"><div class="list-item-paragraph"><p>Find the value of \(u_1\), giving your answer in the form \(a \times 10^k\), where \(1 \leq a \leq 10\) and \(k \in \mathbb{Z}\).</p><span class="inline-marks">[3]</span></div></li></ol>

Consider a geometric sequence, \(u_n\), with common ratio \(r\), where each term in the sequence is positive.
It is given that \(u_6 = 1.6 \times 10^5\) and \(u_8 = 6.4 \times 10^5\).

<p>Find the value of \(u_1\), giving your answer in the form \(a \times 10^k\), where \(1 \leq a \leq 10\) and \(k \in \mathbb{Z}\).</p>

Sequence and Series

International Baccalaureate Mathematics: Analysis and Approaches Standard Level

2026 MAY TZA P1 Q4

2026 MAY TZA P1 Q4