Mathematics 9709 · AS & A Level · Series

Series — practice question

When $(1 - 2x)^2(1 + ax)^6$ is expanded in ascending powers of $x$, the first three terms are $1 - x + bx^2$.

(main)[6]

Find the constants $a$ and $b$.

Worked solution & mark scheme

This 6-mark question has a full step-by-step worked solution and mark scheme. One marking point: “In $(1+ax)^6$, the coefficient of $x$ is $6ax$.” …