A sequence x1,x2,x3,… x_1, x_2, x_3, \dots\,x1,x2,x3,… is defined by
x1=2,x2=9xn=xn−1+xn−2,n≥3 \begin{aligned}x_1 &= 2, x_2 = 9 \\x_n &= x_{n-1} + x_{n-2}, \quad n \geq 3\end{aligned} x1xn=2,x2=9=xn−1+xn−2,n≥3Find x3,x4 x_3, x_4\,x3,x4 and x5x_5x5.
308 exam-style questions on AQA A Level Maths 1.7 D: Sequences and series, covering 1.7.1 Binomial expansion, 1.7.2 Types of sequence (A-level only), 1.7.3 Sigma notation (A-level only), 1.7.4 Arithmetic sequences and series (A-level only), 1.7.5 Geometric sequences and series (A-level only), and 1.7.6 Sequences and series in modelling (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.