Expand (10−x)12\displaystyle (10-x)^{\frac{1}{2}}(10−x)21 in ascending powers of x x\,x up to and including x3x^3x3.
Write down the range of values of x x\,x for which the expansion is valid.
Use your expansion, with x=2x=2x=2, to find an approximation of the value of 2\sqrt{2}2. Give your answer to 3 decimal places.
43 exam-style questions on WJEC A Level Maths 3.4.1 Sequences and Series (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.