Find the first three terms of the expansion of (9+2x)−12\displaystyle (9 + 2x)^{-\frac{1}{2}}(9+2x)−21 in ascending powers of xxx, giving each coefficient in its simplest form.
The expansion of
a+bx9+2x\displaystyle \frac{a + bx}{\sqrt{9 + 2x}}9+2xa+bx
in ascending powers of x x\,x begins 3+x+…3 + x + \dots3+x+…
Find the value of a a\,a and the value of bbb.
200 exam-style questions on CCEA A Level Maths 3.3 Sequences and series (A-level only), covering 3.3.1 Sequences and series (A-level only), 3.3.2 Sequences and series (A-level only), 3.3.3 Sequences and series (A-level only), 3.3.4 Sequences and series (A-level only), 3.3.5 Sequences and series (A-level only), 3.3.6 Sequences and series (A-level only), 3.3.7 Sequences and series (A-level only), and 3.3.8 Sequences and series (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.