Paper 1 October/November 2006 MATHEMATICH (9709/1) A Levels
لطفا برای اطمینان از عملکرد و تجربه بهتر از مرورگرهای مدرن و به روز مانند کروم یا فایرفاکس استفاده کنید.

a) The first and second terms of an arithmetic progression are 161 and 154 respectively. The sum of the first $m$ terms is zero. Find the value of $m$.
b) A geometric progression, in which all the terms are positive, has common ratio $r$. The sum of the first $n$ terms is less than 90% of the sum to infinity. Show that ${r^n} \gt 0.1$.