Mathematics 9709 · AS & A Level · Series

Series — practice question

For the expansion of $(1 + ax)^6$, with $a$ a constant, the coefficient of $x$ is $-30$.

(main)[4]

Find the coefficient attached to $x^3$.

Worked solution & mark scheme

This 4-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Take the term in $x$ from $(1+ax)^6$ as $6ax$” …