Show that 1(2+x)2=2−2(1+12x)−2\displaystyle \frac{1}{(2 + x)^2}=2^{-2}\left(1 + \frac{1}{2}x\right)^{-2}(2+x)21=2−2(1+21x)−2
Work out the first three terms in the binomial expansion of 1(2+x)2\displaystyle \frac{1}{(2 + x)^2}(2+x)21
Write down the range of values of x x\,x for which the expansion is valid.
409 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.