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14+x=12(1+x4)−12 \frac{1}{\sqrt{4+x}}=\frac12\left(1+\frac{x}{4}\right)^{-\frac12} 4+x1=21(1+4x)−21Hence find the first three terms, in ascending powers of xxx, of the binomial expansion of
14+x \frac{1}{\sqrt{4+x}} 4+x1giving each coefficient in its simplest form.
Without evaluating your expansion, state, giving a reason, which of the three values of x x\,x should not be used.
Without evaluating your expansion, state, giving a reason, which of the three values of x x\,x would lead to the most accurate approximation to 3\sqrt{3}3
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.