The electrical current InI_nIn, measured in milliamperes, flowing through a logic gate is monitored at discrete clock cycles. The sequence of current values is defined by the recurrence relation
I1=0.4andIn+1=12Infor n≥1 I_1 = 0.4 \quad \text{and} \quad I_{n+1} = \frac{1}{2I_n} \quad \text{for } n \ge 1 I1=0.4andIn+1=2In1for n≥1Find the values of I2I_2I2, I3I_3I3 and I4I_4I4.
State the period of the sequence.
Determine the exact value of ∑n=1101In\sum_{n=1}^{101} I_n∑n=1101In.
Practise AQA A Level Maths 1.7 D: Sequences and series with exam-style questions for A Level Maths. 267 questions 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), matched to the AQA A Level Maths (7357) specification and written in Paper 1, Paper 2 and Paper 3 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.
