The rate of change of a bio-reactant R R\,R over a period of time t t\,t minutes is modelled by the function:
R(t)=11t+1(1−3t)(t+2),0≤t<13 R(t) = \frac{11t + 1}{(1 - 3t)(t + 2)}, \quad 0 \le t < \frac{1}{3} R(t)=(1−3t)(t+2)11t+1,0≤t<31Express R(t)R(t)R(t) in partial fractions.
(i) Hence find the binomial series expansion of R(t)R(t)R(t) in ascending powers of ttt, up to and including the term in t2t^2t2. Give each coefficient as a simplified fraction.
(ii) State the range of values of t t\,t for which the expansion in (b)(i) is valid.
532 exam-style questions on AQA A Level Maths 1.5 B: Algebra and functions, covering 1.5.1 Laws of indices, 1.5.2 Surds, 1.5.3 Quadratic functions, 1.5.4 Simultaneous equations, 1.5.5 Linear and quadratic inequalities, 1.5.6 Polynomials and rational expressions, 1.5.7 Graphs of functions and proportion, 1.5.8 Composite and inverse functions (A-level only), 1.5.9 Transformations of graphs, 1.5.10 Partial fractions (A-level only), and 1.5.11 Functions in modelling (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.