Question

Геометрична прогресія y1=81, q=-1/3 знайти y2

Answer 1

$y _{1}= 81 \\ q = - \frac{1}{3} \\ y_{n} = y_{1}q {}^{n - 1} \\ y_{2} = y_{1}q = 81 \times (- \frac{1}{3} ) = - 27$