The growth rate H(s)H(s)H(s) of a synthetic crystal, where sss is the concentration of an additive, is modeled by the function:
H(s)=9s+4(1−3s)(2+s)H(s) = \frac{9s + 4}{(1 - 3s)(2 + s)}H(s)=(1−3s)(2+s)9s+4
Express H(s)H(s)H(s) in partial fractions.
Hence find the binomial series expansion of H(s)H(s)H(s) in ascending powers of sss, up to and including the term in s2s^2s2. Give each coefficient as a simplified fraction.
Determine the range of values of sss for which the expansion in (b)(i) is valid.
Practise Edexcel A Level Maths 4.3 Using Partial Fractions with exam-style questions for A Level Maths. 4 questions, matched to the Edexcel A Level Maths (9MA0) 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.