A geometric sequence has first term aaa and common ratio rrr, where r>0r > 0r>0.
Given that
Show that r=0.75r = 0.75r=0.75.
Hence find the value of aaa.
Given that the sum of the first nnn terms of this sequence is greater than 63.5
Find the smallest possible value of nnn.
(Solutions based entirely on graphical or numerical methods are not acceptable.)
326 exam-style questions on Edexcel A Level Maths Sequences and Series, covering 3.1 Arithmetic Sequences, 3.2 Arithmetic Series, 3.3 Geometric Sequences, 3.4 Geometric Series, 3.5 Sum to Infinity, 3.6 Sigma Notation, 3.7 Recurrence Relations, and 3.8 Modelling with Series. Each one has a worked solution and a mark scheme showing where the marks go.