(a)[2]
Write the full expansion of $(x + \frac{2}{x})^5$.
(b)[4]
For $(a + bx^2)(x + \frac{2}{x})^5$, the coefficient of $x$ is zero while the coefficient of $\frac{1}{x}$ is $80$. Determine the constants $a$ and $b$.
Mathematics 9709 · AS & A Level · Series
Series — practice question
Worked solution & mark scheme
This 6-mark question has a full step-by-step worked solution and mark scheme. One marking point: “A correct expansion followed by simplification to $x^5+10x^3+40x+\frac{80}{x}+\frac{80}{x^3}+\frac{32}{x^5}$” …
- Full mark scheme, point by point
- Step-by-step worked solution
- Write your answer & get it marked instantly by AI