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Binomial Expansion

Binomial Expansion

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Question 76

In this question you should assume −15<x<15\displaystyle -\frac{1}{5} < x < \frac{1}{5}−51​<x<51​

a.

For the binomial expansion of (1−5x)−2(1 - 5x)^{-2}(1−5x)−2 find and simplify the first four terms.

[2]
b.

Write down the sum to infinity of the series 1+5x+25x2+125x3+…1 + 5x + 25x^2 + 125x^3 + \dots1+5x+25x2+125x3+…

[1]
c.

Hence or otherwise find and simplify an expression for 2+15x+100x2+625x3+…2 + 15x + 100x^2 + 625x^3 + \dots2+15x+100x2+625x3+…

[3]
Markscheme

Binomial Expansion Questions

  1. A Level
  2. /Maths
  3. /Binomial Expansion

408 exam-style questions on Edexcel A Level Maths Binomial Expansion, covering 4.1 Expanding (1 + x)^n, 4.2 Expanding (a + bx)^n, and 4.3 Using Partial Fractions. Each one has a worked solution and a mark scheme showing where the marks go.

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