Matura czerwiec 2015 zadanie 32 Dany jest nieskończony rosnący ciąg arytmetyczny (an), dla n≥1 taki,

http://akademia-matematyki.edu.pl/ Given an infinite increasing arithmetic sequence (an), for n≥1 such that a5=18. The terms a1, a3, and a13 of this sequence are, respectively, the first, second, and third term of a certain geometric sequence. Determine the formula for the nth term of the sequence (an). Source: Educational Office. Collection of exercises for high schools and technical schools. Marcin Kurczab, Elżbieta Kurczab, Elżbieta Świda. Mathematics 1 Art. 29. Right of Quotation In works constituting a self-contained whole, it is permitted to quote fragments of published works, as well as published works of art, photography, or small works in their entirety, to the extent justified by the purposes of the quotation, such as explanation, polemic, critical or scientific analysis, teaching, or the laws of the creative genre.