Question

Intr-o progresie geometrica (bn) n>1, b2=8 si b1/b3=1/16. Aflati b1.

Answer 1

[tex]\frac{b_1}{b_3}=\frac{1}{q^2}=\frac{1}{16}\Rightarrow q=4\text{ sau }q=-4 \\ b_1=\frac{b_2}{q}\Rightarrow b_1=\frac{8}{4}=2\text{ sau }b_1=\frac{8}{-4}=-2[/tex]