The luminous intensity L L\,L of a specific lamp is measured as a function of the distance d d\,d from the filament. Under certain conditions, the intensity is modeled by
L(d)=(27+4d5)−23 L(d) = \left( 27 + \frac{4d}{5} \right)^{-\frac{2}{3}} L(d)=(27+54d)−32Determine the range of values of d d\,d for which the binomial expansion of L(d)L(d)L(d) in ascending powers of d d\,d is valid.
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.