A sequence u1,u2,u3,… u_1, u_2, u_3, \dots\,u1,u2,u3,… is defined by u3=8,u4=13,u5=21u_3 = 8, u_4 = 13, u_5 = 21u3=8,u4=13,u5=21 and un=un−1+un−2,n≥3u_n = u_{n-1} + u_{n-2}, \quad n \geq 3un=un−1+un−2,n≥3.
Find u1 u_1\,u1 and u2u_2u2.
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.