Відповіді §.19 - §.20 » §.19 (3)

Запишіть перші 4 члени геометричної прогресії (bn), якщо: 1. b1 = 147, bn+1 = b_n/7, b2, b3, b4 – ? b2 = b_1/7 = 147/7 = 21. b3 = b_2/7 = 21/7 = 3. b4 = b_3/7 = 3/7. 2. b1 = 2, bn+1 = √3 bn. b2 = b1 • √3 = 2√3 b3 = b2√3 = 6. b4 = b3√3 = 6√3 3. b3 = –3 bn+1 = –2bn. b2 = b_3/(-2) = 3/2 b1 = b_2/(-2) = –3/2 b4 = –2 • b3 = 6. b5 = –2 • b4 = –12. b6 = b5 • (–2) = 24. 4. b5 = –16 bn+1 = –√2bn b6 = –√2 • (–16) = 16√2 b4 = b_5/(-√2) = (-16)/(-√2) = 8√2 b3 = b_4/(-√2) = (8√2)/(-√2) = –8. b2 = b_3/(-√2) = (-8)/(-√2) = 4√2 b1 = (4√2)/(-√2) = –4.