Find the first 4 terms, in ascending powers of xxx, of the binomial expansion of (1−2x)5(1 - 2x)^5(1−2x)5. Give each term in its simplest form.
If x x\,x is small, so that x2 x^2\,x2 and higher powers can be ignored, show that
(1+x)(1−2x)5≈1−9x. (1 + x)(1 - 2x)^5 \approx 1 - 9x. (1+x)(1−2x)5≈1−9x.Practise Edexcel A Level Old Maths The Binomial Expansion with exam-style questions for A Level Old Maths. 10 questions, matched to the Edexcel A Level Old Maths (9371) specification and written in Unit exams C1, C2, C3 and C4 plus two applied units (e.g. S1 and M1) 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.