Find the first two terms, in ascending powers of uuu, of the binomial expansion of (1+2u)13(1 + 2u)^{\frac{1}{3}}(1+2u)31
Hence, for small values of xxx, show that cos3x+1−x23≈A+Bx+Cx2\cos 3x + \sqrt[3]{1 - x^2} \approx A + Bx + Cx^2cos3x+31−x2≈A+Bx+Cx2 where AAA, BBB and CCC are constants to be found.
Practise Edexcel A Level Maths 4.2 Expanding (a + bx)^n with exam-style questions for A Level Maths. 99 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.