Mathematics 9709 · AS & A Level · Series

Series — practice question

(a)[1]

State the first three terms, in ascending powers of $x$, of the expansion of $(1 + ax)^6$.

(b)[4]

If the coefficient of $x^2$ in the expansion of $(1 - 3x)(1 + ax)^6$ is $-3$, determine the possible values of the constant $a$.

Worked solution & mark scheme

This 5-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Expansion correctly given as $1+6ax+15a^2x^2$” …