Mathematics 9709 · AS & A Level · Series

Series — practice question

(i(a))[2]

Find the first three terms, in ascending powers of $x$, of the expansion of $(1 - x)^6$.

(i(b))[2]

Find the first three terms, in ascending powers of $x$, of the expansion of $(1 + 2x)^6$.

(ii)[3]

Hence find the coefficient of $x^2$ from the expansion of $[(1 - x)(1 + 2x)]^6$.

Worked solution & mark scheme

This 7-mark question has a full step-by-step worked solution and mark scheme. One marking point: $(1-x)^6=1-6x+15x^2$

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