Question

Vă rog ajutați mă la progresia geometrică !

Answer 1

Răspuns:

Explicație pas cu pas:

b₃/b₁ = 216  <=>

(b₁·q²)/b₁ = 216 <=>

q² = 216 <=> q² = 2³·3³

q₁,₂ = ±√(2³·3³) = ±6√6

q⁴ = (±6√6)⁴ = 216² = 46656

q₁⁵ = (-6√6)·216² = -279936√6

q₂⁵ = 6√6·216² = 279936√6

Answer 2

$\it \dfrac{..}{..}\ \ \ \dfrac{b_3}{b_1}=216 \Rightarrow \dfrac{b_1q^2}{b_1}=216 \Rightarrow q^2=216 \Rightarrow (q^2)^2=216^2 \Rightarrow q^4=46656$

$\it q^2=216=36\cdot6=6^2\cdot6 \Rightarrow q=\pm6\sqrt6\\ \\ q^5=q\cdot q^4=\pm6\sqrt6\cdot46656=\pm279936\sqrt6$