Question

в геометрической прогрессии
b8=2^-12, b10=2^-14
b1-?

Answer 1

b₁₀ = b₈* q²
q² = b₁₀ : b₈
q² = 2^ (-14)/2^(-12)
q² = 2^(-2)=(1/2)^2
q = 1/2 = 2^ (-1)
b₈ = b₁*q⁷
b₁ = b₈/q⁷
b₁ = 2^(-12)/2^(-7)
b₁ = 2^ (-5)