Expand 1−2x \sqrt{1-2x}\,1−2x in ascending powers of x x\,x up to and including x3 x^3\,x3 and state the set of values of x x\,x for which the expansion is valid.
Use your expansion to find an approximation for 0.98 \sqrt{0.98}\,0.98 to 5 decimal places.
99 exam-style questions on CCEA A Level Maths 1.3.1 Sequences and series. Each one has a worked solution and a mark scheme showing where the marks go.