Question

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求解！謝謝

2 一等比數列 a,a2, ,a3,其公比為2。若
aaag=1000,試回答下列問題:
(1)a2a3a4 之值為何?(3分)
(2)若 a28d29a30=2″×1000,則n之值為何?(3分

Answer 1

✨ 最佳解答 ✨

綾

a1*a2*a3 = 1000
a2*a3*a4 = a2*a3*(a1*r^3) = 1000*2^3 = 8000

a28*a29*a30
= (a1*r^27)(a2*r^27)(a3*r^27)
= a1*a2*a3*2^(27*3)
= 1000*2^81
n = 81