What is the first term $$a_1$$ and the common ratio $$r$$ of the following geometric sequence if the second, third and fourth terms are: $$-2, -1, -\dfrac{1}{2} $$?

Question

What is the first term $$a_1$$ and the common ratio $$r$$ of the following geometric sequence if the second, third and fourth terms are: $$-2, -1, -\dfrac{1}{2}  $$?

Uniteasy Admin · Accepted Answer

The common ratio $$r =  \dfrac{-1}{-2}  = \dfrac{1}{2}  $$
$$\dfrac{a_2}{a_1} = r  $$

Therefore,
$$ a_1 = \dfrac{a_2}{r}  = \dfrac{-2}{1/2}=-4  $$

Multiple Choice Question (MCQ)

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