Mathematics 9709 · AS & A Level · Series

Series — practice question

(a)[3]

In a geometric progression where every term is positive, the first term is $50$ and the third term is $32$. Find the sum to infinity of this progression.

(b(i))[3]

The three initial terms of an arithmetic progression are $2\sin x$, $3\cos x$ and $(\sin x + 2\cos x)$ respectively, where $x$ is an acute angle. Show that $\tan x = \frac{4}{3}$.

(b(ii))[3]

Find the total of the first twenty terms of the progression.

Worked solution & mark scheme

This 9-mark question has a full step-by-step worked solution and mark scheme. One marking point: Identify the values $a=50$, $ar^2=32$.

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